THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


DARWINISM  AND   HUMAN   LIFE 


DARWINISM  AND 
HUMAN  LIFE 

THE  SOUTH  AFRICAN  LECTURES  FOR  1909 


J.   ARTHUR  THOMSON,    M.A. 

Regius  Professor  of  Natural  History  in  the  University  of  Aberdeen 

AUTHOR  OP  "THE  STUDY  OF  ANIMAL  LIFE,"   "THE  SCIENCE  OF  LIFE," 
"OUTLINES  OF  ZOOLOGY,"    "THE  NATURAL  HISTORY  OF  THE  YEAR," 

"THE  PROGRESS  OF    SCIENCE  IN    THE  CENTURY,"   "HERBERT    SPENCER," 
"HEREDITY,"      "THE     BIBLE  OF     NATURE,"     ETC.;     JOINT     AUTHOR     OF 
-       "THE  EVOLUTION  OF  SEX." 


NEW  YORK 

HENRY  HOLT  AND  COMPANY 
LONDON : ANDREW  MELROSE 


PRINTED  BY 

HAZELL,  WATSON  AND  VINEY,  LD., 

LONDON  AND  AYLESBURY, 

ENGLAND. 


DEDICATION 

This  short  course  of  lectures  on  a  great  theme  is  a  centenary 
tribute  to  Charles  Darwin,  but  7  wish  also  to  ask  the  many 
friends  who  made,  me,  no  stranger  in  their  country — men  and 
women  of  diverse  opinions,  at  one  however  in  their  evolu- 
tionist outlook  and  in  their  good-will — to  lay  it  on  the 
threshold  of  United  South  Africa.  Quod  bonum,  felix 
fauetumque  ait  I 


PREFACE 

IN  1908  the  Lecture  Committee  of  the  South 
African  Association  for  the  Advancement  of  Science 
did  me  the  honour  of  inviting  me  to  give  the 
"  South  African  Lectures "  for  1909,  and  sug- 
gested that,  in  view  of  Darwin's  Centenary,  the 
subject  of  the  course  should  be  Darwinism.  It 
was  the  chief  aim  of  the  lectures  to  explain  the 
gist  of  Darwinism — what  problems  Darwin  set 
himself  to  solve,  and  what  solutions  he  arrived 
at,  and  to  indicate  what  progress  has  been  made 
as  regards  the  problems  of  Organic  Evolution 
since  Darwin's  day — what  has  been  added  to 
Darwinism,  what,  if  anything,  has  been  taken 
away,  and,  especially,  what  is  now  being  recon- 
sidered. An  endeavour — necessarily  straitened  by 
the  limits  of  the  course — was  also  made  to  suggest 
how  Darwinism  touches  everyday  life,  in  farm  and 
garden,  in  city  and  empire. 


vU 


CONTENTS 

CHAPTER   I 
WHAT  WE   OWE   TO    DARWIN 

Biographical — Darwin's  Books — The  Naturalist's  Problems — The 
first  Question  :  What  is  This  ? — The  second  Question  :  How  does 
This  work  ? — The  third  Question  :  Whence  is  This  ? — The  fourth 
Question  :  How  have  Present-day  Organisms  come  to  be  as  they 
are  ? — Manifoldness  of  Darwin's  Services — The  Web  of  Life — The 
Struggle  for  Existence — Variability  of  Living  Creatures — Natural 
Selection — Vindication  of  the  Evolution  Idea — The  Evolution 
Theory,  a  Modal  Interpretation — Darwin's  Argument — Comparison 
of  Evolution  Formula  and  Gravitation  Formula — The  Descent  and 
the  Ascent  of  Man — Liberation  of  Intelligence — Ideal  of  Scientific 
Mood  and  Method — Characteristics  of  Scientific  Mood  :  Passion  and 
Reverence  for  Facts — Scientific  Caution — Clearness  of  Vision — 
Sense  of  Interrelations — Darwin's  Method  of  Working — Darwin  on 
his  own  Success — Darwin's  Achievements — Co-operating  Influences 
— Particular  Reasons  for  Darwin's  Success  .  .  .  pp.  3-42 


CHAPTER   II 
THE   WEB   OF  LIFE 

Correlation  of  Organisms  as  well  as  Correlation  of  Organs — What 
the  Metaphor  of  "  The  Web  of  Life  "  suggests — Dependence  of  Living 
Creatures     upon     their     Surroundings — Nutritive     Chains — Nexus 
ix 


x  CONTENTS 

between  Mud  and  Clear  Thinking — Correlation  between  Catches  of 
Mackerel  and  Amount  of  Spring  Sunshine — Nutritive  Chains  in  the 
Deep  Sea — Dependence  of  one  Organism  on  another  for  the  Con- 
tinuance of  the  Species — Darwin's  Instance  of  the  Connection 
between  Cats  and  Clover — Scattering  of  Seeds — Interrelations 
between  Freshwater  Mussels  and  Fishes — Life-histories  of  Parasites 
— Far-reaching  Influence  of  Certain  Animals  :  Earthworms — Ter- 
mites, or  White  Ants — The  Hand  of  Life  upon  the  Earth — Practical 
Importance  of  a  Realisation  of  the  Web  of  Life  .  .  pp.  45-65 


CHAPTER   III 
THE   STRUGGLE   FOR   EXISTENCE 

The  Idea  not  so  Simple  as  it  seems — The  Anthropomorphism  of 
the  Idea — Different  Forms  of  the  Struggle  for  Existence — Struggle 
for  Existence  in  the  Plant  World — Illustration  of  the  Complexity 
of  the  Struggle  for  Existence — Reasons  for  the  Struggle  for  Existence 
— Results  of  the  Struggle  for  Existence — Breadth  of  the  Darwinian 
Concept  of  the  Struggle  for  Existence — The  other  Side  of  the 
Struggle  for  Existence — Mutual  Aid — Application  of  the  Concept 
to  Human  Life .  pp.  69-94 


CHAPTER    IV 
THE   RAW   MATERIALS   OF  PROGRESS 

Organic  Progress  Primarily  depends  on  Variability — Darwin's 
Position — Progress  since  Darwin's  Day  in  Regard  to  Variation — 
Variations  more  Abundant  than  even  Darwin  supposed — Proportion 
between  Frequency  and  Amount  of  Variations — Correlation  of 
Variations — Brusque  Variations  more  Frequent  than  wan  formerly 
supposed — Discontinuous  Variations — Mutations — Darwin's  Posi- 
tion in  Regard  to  Mutations— Origin  of  Variations— Germinal 
Selection — Variational  Stimuli— Modifications  or  Acquired  Charac- 
ters— Indirect  Importance  of  Modifications — Modification-Species — 
Individual  Plasticity— Relation  to  Human  Life  .  pp.  97-126 


CONTENTS 


CHAPTER   V 
FACTS   OF  INHERITANCE 

Progress  during  the  Darwinian  Era — Demonstration  of  Heritable 
Qualities — Heredity,  a  Term  for  the  Genetic  Relation  between 
Successive  Generations — Appreciation  of  Distinction  between 
Nature  and  Nurture — The  Idea  of  the  Continuity  of  Generations — 
Critical  Attitude  in  Regard  to  Various  Conclusions — Mendelism — 
Methods  of  Studying  Heredity — Microscopical  Study  of  the  Germ- 
cells — Statistical  Study :  Filial  Regression — Galton's  Law  of 
Ancestral  Inheritance — Experimental  Study — Pairing  of  Similar 
Pure-bred  Forms — Blending— Particulate  Inheritance — Exclusive 
Inheritance — Reversion — New  Departures — Mendelian  Inheritance 
— Unit  Characters — The  Case  of  Andalusian  Fowls — Waltzing  Mice 
— Occurrence  of  Mendelian  Inheritance — Practical  Importance  of 
Mendelism — Much  Progress  but  Great  Uncertainty — Transmission 
of  Acquired  Characters — Disease — Facts  and  Possibilities — A 
Striking  Case— Logical  Position  of  the  Question — Cases  where 
the  Theory  of  Modification-inheritance  is  Inapplicable — Im- 
portance of  Environment  and  Function  Remains — Selaction  and 
Stimulus — Indirect  Importance  of  Modifications — Practical  Im- 
port of  the  Question  as  to  the  Transmission  of  Acquired 
Characters — Inheritance  of  Moral  Character — Three  General 
Conclusions  .  pp.  129-177 


CHAPTER    VI 
SELECTION  :     ORGANIC   AND    SOCIAL 

Influence  of  Malthus— Darwin's  Position — The  Theory  stated — 
The  Theory  of  Natural  Selection  to  be  tested  as  an  Interpretative 
Formula — Illustrations  of  Natural  Selection — Objections  and 
Criticisms — Adaptations— Changes  since  Darwin's  Day — Evidences 
of  Natural  Selection — Lessening  the  Burden  of  the  Theory — Sexual 
Selection — Isolation — Gradual  Diminution  of  Natural  Selection  in 


xii  CONTENTS 

Mankind — Contrast  between  the  Human  Race  and  the  Animal 
World — Some  Natural  Selection  remains — The  Dilemma  of  Civilisa- 
tion— The  extreme  laissez-faire  Position — Social  Surgery — How  far 
is  Social  Selection  compensating  for  Diminished  Natural  Selection? — 
Reversed  Selection  in  Human  Society — Summary  of  the  Argument — 
Constructive  Suggestions — Selection  of  Eutopias — Selection  of 
Healthful  Occupations — Eugenic  Selection.  .  .  pp.  181-237 


REPRESENTATIVE  BOOKS  ON  DARWINISM  .    pp.  241-245 


CHAFrER  I 
WHAT  WE  OWE  TO  DARWIN 


CHAPTER   I 

WHAT  WE   OWE  TO   DARWIN 

Biographical — Darwin's  Books — The  Naturalist's  Problems — The 
first  Question  :  What  is  This  ? — The  second  Question  :  How 
does  This  work  ? — The  third  Question  :  Whence  is  This  ? 
— The  fourth  Question  :  How  have  Present-day  Organisms 
come  to  be  as  they  are  ? — Manifoldness  of  Darwin's  Services 
— The  Web  of  Life — The  Struggle  for  Existence — Variability 
of  Living  Creatures — Natural  Selection — Vindication  of  the 
Evolution  Idea — The  Evolution  Theory,  a  Model  Interpreta- 
tion— Darwin's  Argument — Comparison  of  Evolution  Formula 
and  Gravitation  Formula — The  Descent  and  the  Ascent  of 
Man — Liberation  of  Intelligence — Ideal  of  Scientific  Mood 
and  Method — Characteristics  of  Scientific  Mood  :  Passion  and 
Reverence  for  Facts — Scientific  Caution — Clearness  of  Vision 
— Sense  of  Interrelations — Darwin's  Method  of  Working — 
Darwin  on  his  own  Success — Darwin's  Achievements — Co- 
operating Influences — Particular  Reasons  for  Darwin's  Success. 

BIOGRAPHICAL. — Charles  Darwin,  the  greatest  natu- 
ralist who  has  yet  lived,  was  born  at  Shrewsbury 
on  February  12,  1809,  on  the  same  day  as  Abraham 
Lincoln.  Indeed  the  year  was  one  of  remarkable 
children,  for  it  saw  the  birth  of  Tennyson  and 
Gladstone,  of  Chopin  and  Mendelssohn,  of  Mrs. 
Browning  and  Fanny  Kemble,  of  Edgar  Allan 
Poe  and  John  Hill  Burton,  of  Edward  Fitzgerald 
and  Oliver  Wendell  Holmes,  and  many  more.  We 
shall  not  compare  Darwin  with  any  of  the 
illustrious  personalities  whom  we  have  named, 
for  the  comparison  of  incommensurables  is  always 
unprofitable ;  but  without  exaggeration,  which 

3 


4  DARWINISM  AND   HUMAN  LIFE 

should  be  absent  from  scientific  discourse,  it  may 
be  said  that  no  other  man  of  science  has  influenced 
the  framework  of  human  thought  as  Darwin  has 
done.  We  propose,  first  of  all,  to  recall  very  briefly 
the  leading  facts  of  his  life. 

Darwin's  inheritance  must  have  given  him  a 
scientific  bent.  His  grandfather,  Erasmus  Darwin, 
the  author  of  "  Zoonomia  "  (1794)  was  a  thoughtful 
evolutionist ;  his  father,  Robert  Waring  Darwin, 
also  a  physician,  had  an  unusually  keen  faculty 
of  observation ;  his  mother  was  a  daughter  of 
Josiah  Wedgwood,  the  founder  of  the  famous 
pottery  works ;  and  it  may  be  further  noted  that 
Sir  Francis  Galton  is  Darwin's  cousin.  In  addi- 
tion to  actual  inheritance,  there  was  another 
influence  which  would  tend  to  direct  Darwin's 
mind  towards  science,  namely,  the  scientific  atmo- 
sphere and  tradition  of  his  home. 

As  a  boy  Darwin  was  strong  and  active ;  he 
was  fond  of  open-air  life,  and  he  made  nothing 
of  the  classical  school  to  which  he  was  sent.  In 
1825  he  went  with  his  brother  to  Edinburgh  with 
the  purpose  of  studying  medicine ;  but  he  found 
the  lectures  "  intolerably  dull "  and  made  little 
of  them.  He  got  to  know  several  naturalists, 
however,  and  made  his  first  discovery — in  regard 
to  the  development  of  the  sea-mat  (Flustra).  After 
two  sessions  at  Edinburgh  he  went  to  Cambridge 
with  the  vague  view  of  becoming  a  clergyman  ;  but 
of  this  period  he  writes  :  "  During  the  three  years 
which  I  spent  at  Cambridge  my  time  was  wasted, 
so  far  as  academical  studies  were  concerned,  as 
completely  as  at  Edinburgh  and  at  school." 

During  his  stay  at  Cambridge  he  kept  up  his 
boyish  beetle-collecting  and  indulged  his  fondness 


WHAT    WE    OWE   TO   DARWIN  5 

for  riding  and  shooting.  He  came  under  the 
influence  of  Professor  Henslow,  the  botanist,  who 
advised  him  to  read  Lyell's  "  Principles  of 
Geology,"  and  was  instrumental  in  sending  him 
off  on  the  Beagle. 

Of  the  Beagle  voyage,  which  extended  for  five 
years  (1831-6),  mainly  spent  along  the  coasts  of 
South  America,  Darwin  says  :  "  This  was  by  far  the 
most  important  event  in  my  life,  and  has  deter- 
mined my  whole  career."  He  learned  to  work 
hard,  he  accumulated  a  wealth  of  impressions,  and 
he  had  time  to  think.  On  one  of  his  land  journeys 
over  the  Pampas  he  was  struck  by  the  resemblances 
between  living  and  extinct  forms,  and  wrote :  "  This 
wonderful  relationship  in  the  same  continent 
between  the  dead  and  the  living  will,  I  do  not 
doubt,  hereafter  throw  more  light  on  the  appearance 
of  organic  beings  on  our  earth,  and  their  dis- 
appearance from  it,  than  any  other  class  of  facts." 
The  savage  character  of  the  natives  at  Tierra  del 
Fuego  and  the  individuality  of  the  fauna  on  the 
various  Galapagos  islands  were  seed-impressions 
which  afterwards  bore  fruit  in  thought. 

For  six  years  after  returning  from  the  Beagle 
voyage,  Darwin  worked  in  London  at  his  collections, 
especially  at  the  geological  specimens.  He  pub- 
lished his  "  Naturalist's  Voyage  "  in  1839,  and  in 
the  same  year  married  his  cousin,  Emma  Wedg- 
wood. As  his  health  had  not  been  good  after  his 
return  from  the  Beagle,  he  left  London  in  1842, 
and  settled  in  a  country  house  at  Down.  There 
in  quiet  industry,  badly  hampered  by  ill  health, 
he  spent  the  rest  of  his  life.  He  died  on  April  19, 
1882,  one  of  the  great  Immortals  among  men. 

DARWIN'S  BOOKS. — The  forty  years  at  Down 


6  DARWINISM   AND    HUMAN    LIFE 

were  punctuated  by  the  completion  of  book  after 
book — the  "  milestones  of  my  life,"  as  he  called 
them ;  and  it  may  be  useful  to  note  that  Darwin 
recognised  three  stages  in  his  career  as  a  biologist : 
(1)  the  mere  collector  at  Cambridge ;  (2)  the 
collector  and  observer  on  the  Beagle  voyage  (to 
which  he  thought  he  owed  "  the  first  real  training 
and  education  "  of  his  mind) ;  and  (3)  the  trained 
naturalist  after  his  eight  years'  work  on  barnacles. 

His  books  may  be  arranged  in  three  groups  : 

(a)  The  early  zoological  and  geological  studies, 
e.g.  "  Zoology  and  Geology  of  the  Beagle  "  (1840- 
46),  "  Coral  Keefs  "  (1842),  "  Monograph  on  the 
Cirripedia"  (1846-54).  Although  the  book  on 
Earthworms  was  not  published  till  1881,  it  was 
begun  more  than  forty  years  before,  and  may  be 
included  in  the  first  series. 

(6)  The  series  of  evolutionary  volumes  :  "  The 
Origin  of  Species"  (1859);  "Variation  of  Ani- 
mals and  Plants  under  Domestication  "  (1868)  ; 
"  Descent  of  Man  "  (1871) ;  "  Expression  of  the 
Emotions  "  (1872). 

(c)  The  botanical  books — largely  influenced  by 
evolutionary  ideas  :  "  Fertilisation  of  Orchids  " 
(1862)  ;  "  Movements  and  Habits  of  Climbing 
Plants  "  (1875) ;  "  Insectivorous  Plants  "  (1875) ; 
"  Cross  and  Self-fertilisation  in  Plants  "  (1876) ; 
"  The  Different  Forms  of  Flowers  in  Plants  of  the 
same  Species  "  (1877) ;  "  The  Power  of  Movement 
in  Plants  "  (1880). 

THE  NATURALIST'S  PROBLEMS. — It  may  be  useful 
to  inquire  into  the  aims  and  methods  of  naturalists 
in  general,  if  we  are  rightly  to  appreciate  the 
services  rendered  by  the  greatest  of  them  all.  The 
problems  appear  at  first  sight  to  be  numerous  and 


WHAT   WE    OWE   TO    DARWIN  7 

varied,  but,  from  a  certain  distance,  we  see  that 
naturalists  ask  only  four  questions  :  What  is  this 
living  creature  ?  How  does  it  work  ?  Whence 
has  it  arisen  ?  How  has  it  come  to  be  as  it 
is  ?  Darwin  asked  each  of  these  questions,  but, 
after  serving  his  apprenticeship  in  answering  the 
first  three — for  he  was  anatomist,  physiologist, 
and  palaeontologist  in  turn — he  settled  down  to 
the  fourth — the  question  of  questions — How  have 
living  creatures  come  to  be  as  they  are  ? 

The  Question  What  is  This?— The  naturalist's 
first  question — however  learnedly  he  may  phrase 
it — is  one  of  the  child's  first  questions,  asked  long 
before  it  can  speak  :  "  What  is  this  ?  "  In  how 
many  different  tones — of  fear,  of  awe,  of  wonder, 
of  inquisitiveness — has  this  question  been  asked 
since  man  and  science  began !  Was  it  not 
Aristotle's  question  when  a  new  specimen  was 
brought  to  him  ?  Was  it  not  the  question  of 
the  naturalist  on  the  Challenger  when  the  dredge 
came  up  ?  Is  it  not  the  question  on  the  lips  of 
every  teacher  and  student  of  natural  history 
to-day  ? — What  is  this  ?  It  is  a  "  simple  ques- 
tion," but  how  hard  to  answer,  as  we  press  it 
further  and  further  home,  from  external  features 
to  internal  structure,  from  organs  to  tissues,  from 
tissues  to  cells,  as  we  put  one  lens  after  another  in 
front  of  OUT  own,  as  we  call  to  our  aid  all  sorts 
of  devices — scalpel  and  forceps,  razor  and  micro- 
tome, fixative  and  stain !  "  What  is  this,"  we 
say,  "  in  itself  and  in  all  its  parts  ?  what  is  this  by 
itself  and  when  compared  with  its  fellows  and 
kindred  ?  ",  and  our  answer  broadens  and  deepens 
till  it  furnishes  the  raw  materials  of  the  science  of 
morphology. 


8          DARWINISM  AND   HUMAN   LIFE 

The  Question  How  does  This  work? — But  close 
upon  the  first  question — What  is  this  ?  there  rises  a 
second — How  does  this  work  ?  It  is  equally  natural 
and  necessary,  and  throughout  the  progressive 
periods  in  the  history  of  biology  the  two  questions 
have  never  been  far  apart.  They  have  evolved 
together  especially  during  the  last  hundred  years, 
prompting  one  another  to  a  more  and  more  pene- 
trating inquisitiveness.  The  key-word  of  the  one 
is  structure,  or  organisation ;  of  the  other  function, 
or  activity.  The  creature  which  our  first  question 
killed  and  picked  to  pieces  has  to  be  put  together 
again  and  made  to  work.  What  does  it  do  ?  how 
does  it  do  it  ?  how  does  it  go  ?  how  does  it  keep 
a-going  ?  how  does  it  set  other  creatures  like  itself 
a-going  ?  how  long  can  it  go  ?  how  does  it  cease 
from  going  ?  In  other  words,  how  does  the 
organism  feel  and  move  ?  how  does  it  grow  and 
multiply  ?  how  does  it  waste,  recover  itself,  and 
finally,  in  most  cases,  die  ?  Above  all,  what 
is  the  secret  of  its  activity  and  of  its  power  of 
effective  response  to  the  order  of  nature  ?  These 
are  some  of  the  physiological  problems  which 
recall  Clerk  Maxwell's  boyish  question — "  What  is 
the  go  of  this — the  particular  go  of  this  ?  " 

The  Question  Whence  is  This  ? — A  third  question 
is — Whence  is  this  ?  and,  though  it  is  probably 
as  ancient  as  the  others,  the  answering  of  it  is 
distinctly  modern.  It  is  really  a  double  question, 
for  we  may  inquire  into  the  development — the 
becoming — of  the  individual,  and  we  may  in- 
quire into  the  history  of  the  race  to  which  the 
individual  belongs.  We  may  study  the  child- 
animal  in  its  cradle — the  bee-grub  in  the  comb, 
the  embryo  skate  in  its  mermaid's  purse,  the 


WHAT   WE    OWE   TO    DARWIN  9 

chick  within  the  egg-shell — and  the  answer  to  the 
question — Whence  came  this  individual  animal 
as  a  whole  and  in  each  of  its  parts  ?  is  embryology. 
On  the  other  hand,  we  may  study  the  history  of 
the  race  as  it  is  hidden  in  the  strange  graveyards 
of  the  buried  past,  the  fossil-bearing  rocks,  and 
the  answer  to  the  question — Whence  came  this 
race  ?  is  palaeontology. 

The  Question  How  have  Present-day  Organisms 
come  to  le  as  they  are? — There  remains  a  fourth 
question,  also  ancient,  but  since  Darwin's  day 
asked  with  a  new  hopefulness — How  have  these 
living  creatures  come  to  be  as  they  are  ?  They  have 
had  a  history — a  slow  racial  evolution — as  surely 
as  they  have  an  individual  development.  We 
have  got  a  firm  grasp  of  the  modal  theory — that 
the  present  is  the  child  of  the  past,  but  the  causal 
theory  is  still  being  evolved.  The  idea  of  evolution 
is  the  most  potent  thought-economising  formula 
which  the  world  has  yet  known,  but  as  to  the 
factors  in  evolution  we  are  still  only  inquiring. 
What  are  the  originative  and  what  the  directive 
factors  ?  How  has  the  raw  material  of  progress, 
which  we  call  variation,  been  made  available 
throughout  the  countless  ages  ?  and  how  has  this 
raw  material  been  fashioned  to  shape  and  use  ? 

MANIFOLDNESS  OF  DARWIN'S  SERVICES. — What 
do  we  owe  to  Darwin  ?  It  is  the  meed  of  greatness 
to  receive  manifold  tribute.  For  how  many  diverse 
reasons  has  Shakespeare  the  world's  homage  !  A 
great  life-work  is  like  a  great  picture ;  this  character 
appeals  to  me  and  that  to  you.  So  some  say  that 
what  we  most  owe  to  Darwin  is  our  evolutionist  out- 
look, while  others  emphasise  the  idea  of  selection, 
and  others  the  demonstration  that  the  problems 


10         DARWINISM   AND    HUMAN   LIFE 

of  heredity  and  variation  are  amenable  to 
scientific  analysis,  and  others  that  he  first  clearly 
showed  the  affiliation  of  man  to  the  rest  of  creation. 
The  fact  is  that  Darwin  focussed  so  many  ideas 
that  were  previously  dim,  and  made  so  many  old 
facts  new,  and  gave  us  keys  to  so  many  doors,  that 
it  is  a  matter  of  opinion  which  of  his  services  was 
greatest.  This,  at  least,  is  certain:  that,  when 
we  have  thought  for  an  hour  of  what  we  owe  to 
Darwin,  we  shall  not  have  discovered  how  much 
that  is.  For  his  intellectual  legacy  is  still  earning 
interest  and  increasing  our  wealth.  His  leaven 
will  go  on  fermenting  till  the  whole  is  leavened. 
Then  it  will  be  time  for  a  new  yeast. 

(I)  THE  WEB  OF  LIFE. — What  do  we  owe  to 
Darwin  ?  We  give  precedence  to  Darwin's  picture 
of  "  The  Web  of  Life/'  the  service  that  appeals 
most  to  the  naturalist,  to  whom  the  conception  is 
absolutely  fundamental.  It  lies  below  the  idea  of 
the  Struggle  for  Existence,  and  therefore  below  the 
idea  of  Natural  Selection.  It  is  a  fact  of  life  which 
will  remain,  however  theories  may  change.  It 
is  a  fine  idea  to  dream  over  and  to  work  with. 

What  is  meant  by  Darwin's  picture  of  the  Web 
of  Life,  and  where  did  he  paint  it  ?  We  find  it 
in  all  his  works — a  luminous  background — the 
idea  of  linkages  in  nature,  the  idea  of  the  corre- 
lation of  organisms.  Cats  have  to  do  with  the 
clover  crop,  Darwin  says,  and  earthworms  with 
the  world's  bread  supply.  If  there  is  an  orchid  in 
Madagascar  with  a  spur  eleven  inches  long,  Darwin 
prophesies  that  there  is  a  moth  with  a  proboscis 
of  equal  length.  No  bird  falls  to  the  ground 
without  sending  a  throb  through  a  wide  circle,  for 
Darwin  rears  eighty  seedlings  from  a  single  clod 


WHAT    WE    OWE   TO    DARWIN  11 

taken  from  a  bird's  foot.  Long  nutritive  chains 
bind  the  bracken  on  the  hill-side  to  the  brain 
of  the  proprietor — if  he  is  fond  of  eating  trout. 
The  patent-leather  shoes  on  his  feet  connect  him 
with  the  melancholy  slaughter  of  seals,  while 
his  ivory-backed  toilet-brushes  implicate  him  in 
the  passing  of  the  elephant.  There  is  a  ceaseless 
circulation  of  matter  and  energy.  All  things 
flow.  Influence  passes  from  A.  to  Z.,  though 
Z.  is  quite  unaware  of  A.  What  ripples  spread 
and  spread  from  the  introduction  of  rabbits  into 
Australia,  or  of  sparrows  into  the  United  States, 
or  of  the  mongoose  into  Jamaica  !  What  abso- 
lutely essential  connections  there  are  between 
cutting  down  trees  and  a  plague  of  insects,  between 
birds  and  seed-scattering,  between  sunlight  and 
the  catches  of  mackerel ! 

Take  an  instance  from  "  The  Origin  of  Species  " : 
"  If  certain  insectivorous  birds  were  to  decrease 
in  Paraguay,  the  parasitic  insects  would  probably 
increase ;  and  this  would  lessen  the  number  of 
navel-frequenting  flies — then  cattle  and  horses 
would  become  feral,  and  this  would  certainly 
greatly  alter  (as  indeed  I  have  observed  in  parts  of 
South  America)  the  vegetation  ;  this,  again,  would 
largely  affect  the  insects  ;  and  this,  as  we  have  just 
seen  in  Staffordshire,  the  insectivorous  birds,  and 
so  onwards  in  ever-increasing  circles  of  complexity." 

(II)  THE  STRUGGLE  FOR  EXISTENCE. — What  do 
we  owe  to  Darwin  ?  In  the  second  place,  we  may 
rank  his  realisation  of  "  the  struggle  for  exist- 
ence." From  Aristotle  to  Lucretius,  from  Buffon 
to  Robert  Chambers,  there  had  been  allusion  to 
the  struggle  for  existence  in  nature,  and  every  one 
knows,  for  instance,  how  it  recurs  repeatedly  in 


12         DARWINISM   AND   HUMAN   LIFE 

Tennyson's  "  In  Memoriam,"  which  was  written 
before  "  The  Origin  of  Species."  The  poet  speaks 
of  Nature  "  red  in  tooth  and  claw  with  ravine  "  ; 
"  so  careless  of  the  single  life  "  ;  "  of  fifty,"  or 
(as  he  afterwards  suggested)  "  of  myriad  seeds 
she  often  brings  but  one  to  bear."  But  it  is  certain 
that  no  one  before  Darwin  realised  the  length 
and  breadth,  the  height  and  depth,  of  the  struggle 
for  existence.  His  realisation  of  it  is  "  bigger  " 
than  that  of  most  of  his  successors.  Darwin 
recognised  the  struggle  between  Fellows,  the 
struggle  between  Foes,  and  the  struggle  be- 
tween Living  Creatures  and  the  Physical  Forces. 
(A)  There  is  cannibalism  in  the  cradle  in  the 
egg-capsules  of  the  buckie  and  the  dog-whelk ; 
locust  may  eat  locust  when  the  worst  comes  to 
the  worst ;  stag  may  fight  to  the  death  with 
stag  in  the  forest  clearing;  certain  mountain- 
varieties  of  sheep  will  starve  out  other  mountain- 
varieties  ;  the  sister  seedlings  compete  together 
in  the  plot :  that  is  Struggle  between  Fellows.  We 
may  extend  this  category  of  competition  between 
individuals  of  the  same  species  to  include  com- 
petition between  individuals  of  nearly  related 
species,  though  what  is  involved  in  the  step  should 
be  carefully  noticed.  If  we  make  the  extension, 
however,  we  include  Darwin's  well-known  case 
of  brown  rat  versus  black  rat.  The  other  illus- 
trations he  gave  concerned  two  kinds  of  thrush, 
two  kinds  of  swallow,  two  kinds  of  cockroach,  and 
two  kinds  of  charlock.  (B)  Secondly,  the  world 
is  full  of  competition  and  struggle  between  living 
creatures  not  nearly  related  to  one  another — 
between  fox  and  hare,  between  stoat  and  rabbit, 
between  mongoose  and  snake,  and  so  on,  end- 


WHAT    WE    OWE    TO    DARWIN  13 

lessly :  that  is  Struggle  between  Foes.  The  foes 
do  not  need  to  be  well  matched.  Alfred  Russel 
Wallace  has  recently  told  us  of  a  pair  of  blue  tits, 
with  a  large  family,  who  worked  for  sixteen  hours 
a  day  at  midsummer,  and  it  was  estimated  that 
they  captured  in  that  time  about  two  thousand 
caterpillars  and  grubs.  A  locust-bird  at  work  is 
another  good  instance  of  a  one-sided  struggle. 
Nor  do  the  foes  need  to  compete  directly — it  will 
suffice  if  both  seek  the  same  food,  the  same  locality, 
the  same  anything,  (c)  Darwin  recognised  a 
third  great  mode  of  the  struggle  for  existence 
when  he  spoke,  for  instance,  of  a  plant  on  the 
edge  of  the  desert  struggling  for  life  against  the 
drought,  and  of  the  birds  struggling  against  the 
winter.  This  is  the  Struggle  with  Fate. 

As  a  number  of  illustrious  living  naturalists 
persist  in  maintaining  that  what  Darwin  mainly 
thought  of  was  the  struggle  between  near  kin — 
for  room  in  the  nest,  for  food  at  the  platter, 
for  foothold  on  the  rock,  and  so  on,  we  must 
remember  Darwin's  emphatic  statement  that  he 
used  the  term  "in  a  large  and  metaphorical 
sense."  He  speaks  of  two  "  canine  animals " 
struggling  with  each  other  in  a  time  of  dearth ; 
of  mistletoe  versus  mistletoe  on  the  same  branch ; 
of  mistletoe  versus  other  fruit-bearing  plants ; 
of  a  plant  on  the  edge  of  the  desert  in  days  of 
drought ;  and  then  says,  "  In  these  several  senses, 
which  pass  into  each  other,  I  use,  for  convenience' 
sake,  the  general  term  of  Struggle  for  Existence." 
The  fact  is  that  the  "  struggle  for  existence  "  is  a 
formula-phrase  including  all  the  reactions  and 
endeavours  of  living  creatures  in  face  of  difficulties 
and  limitations. 


14         DARWINISM   AND    HUMAN   LIFE 

(III)  VARIABILITY  OF  LIVING  CREATURES. — What 
do  we  owe  to  Darwin  ?  A  vivid  presentation  of 
the  idea  of  variability,  or  organic  flux.  There  had 
been,  of  course,  transformists  before  his  day,  but 
either  they  had  not  the  idea  very  clearly  in  their 
own  minds  or  they  failed  in  making  it  convincing 
to  others.  So  it  was  that  Darwin  had  to  make 
way  against  the  general  conviction  of  contemporary 
naturalists  that  species  were  fixed.  In  1844  he 
wrote  to  Hooker :  "  I  am  almost  convinced  .  .  . 
that  species  are  not  (it  is  like  confessing  a  murder) 
immutable."  The  idea  seems  to  have  suggested 
itself  more  than  once  on  the  Beagle  voyage ;  for 
instance,  when  he  found  fossils  in  Argentina  very 
like  living  forms  and  yet  different. 

In  forming  his  impression  of  the  variability  of 
living  creatures  Darwin  depended  on  what  has 
taken  place  in  domestication  and  cultivation, 
on  the  experience  gained  in  his  systematic  work 
that  specific  characters  are  far  from  being  constant, 
and  that  so-called  varieties  often  link  species  to 
species.  A  species  is  a  group  of  similar  individuals 
of  common  descent,  capable  of  pairing  together, 
and  breeding  more  or  less  true.  It  may  be  repre- 
sented by  a  constellation  of  dots,  densest  towards 
the  centre  (which  means  that  the  great  majority 
are  very  like  one  another)  and  thinning  out  to- 
wards the  periphery  where  the  variants  extend 
as  outliers  in  different  directions.  When  we 
begin  to  study  a  corner  of  the  zoological  sky  it 
seems  to  be  covered  with  very  distinct  constella- 
tions, and  it  is  all  clear ;  but  in  many  cases  deeper 
study  shows  that  one  constellation  is  connected 
with  another  by  outliers,  and  that  there  is  con- 
tinual flux. 


WHAT   WE   OWE   TO   DARWIN  15 

Darwin  recognised  the  occurrence  of  structural 
changes  directly  due  to  changed  surroundings 
and  changed  habits,  which  he  called  "  definite 
variations,"  which  are  now  usually  called  modi- 
fications, or  "acquired  characters";  and  he  believed 
that  these  were,  in  some  cases,  transmitted.  This 
is  the  characteristic  Lamarckian  position.  But  the 
raw  materials  of  progress  which  Darwin  chiefly 
relied  on  were  what  he  called  the  "  numerous,  suc- 
cessive, slight,  favourable  variations  "  ("  Origin  of 
Species,"  p.  421).  He  also  took  account  of  "  sudden 
and  considerable  deviations  of  structure  " — "  single 
or  occasional  variations,"  as  he  called  them ;  but 
he  very  deliberately  refrained  from  attaching 
importance  to  such  leaps  and  bounds,  thinking 
that  they  had  no  staying  power  in  inheritance. 
As  to  the  causes  of  the  inborn  variations  in  living 
creatures,  Darwin  had  no  light,  and,  with  his 
characteristic  candour,  said  so. 

(IV)  NATURAL  SELECTION. — What  do  we  owe 
to  Darwin?  The  theory  of  Natural  Selection, 
which  his  magnanimous  fellow-worker,  Alfred 
Russel  Wallace,  independently  stated  at  the  same 
time  (1858),  and  of  which  there  had  been  a  few 
previous  suggestions  of  a  more  or  less  vague  de- 
scription. It  was  here  that  Darwin's  originality 
was  greatest,  for  he  revealed  the  many  different 
forms — often  very  subtle — which  Natural  Selection 
takes,  and,  with  the  insight  of  a  disciplined  scientific 
imagination,  he  realised  what  a  mighty  engine  of 
progress  it  has  been  and  is.  His  theory  is  simple 
and  admits  of  brief  statement.  We  can  under- 
stand Huxley's  remark  :  "  How  extremely  stupid 
not  to  have  thought  of  that !  " 

(1)  Variability  is  a  fact  of  life.    The  members  of 


16         DARWINISM   AND   HUMAN   LIFE 

a  family  or  of  a  species  are  not  born  alike  :  some 
have  qualities  which  give  them  a  little  advantage 
both  as  to  hunger  and  as  to  love ;  others  are 
relatively  handicapped.  We  may  not  understand 
their  origin,  but  we  know  that  useful  variations 
occur. 

(2)  A  struggle  for  existence  is  also  a  fact  of 
life — a    struggle    for  existence    in    an    intricate 
web  of  interrelations.    It  operates  whenever  there 
is  disturbance  of  equilibrium  or  clashing  of  inter- 
ests, whenever  the  living  creature  makes  effective 
responses  to  the  limitations  closing  in  upon  it. 

(3)  In  certain  forms  of  the  struggle  for  existence 
the  relatively  less  fit  forms  are  eliminated,  which 
does   not  necessarily   mean   that   they   come   at 
once  to  a  violent  end,  but  often  simply  that  they 
die  before  the  average  time  and  are  less  successful 
than  their  neighbours  as  regards  their  offspring. 
The  result  is  that  the  relatively  more  fit  tend 
to  survive,  and  to  become  the  majority.    The  fit- 
ness may  refer  to  the  whole  constitution,  or  to  a 
particular  character. 

(4)  As  many  variations  are  transmitted  from 
generation  to  generation,  and  may,  through  the 
pairing  of  similar  or  suitable  mates,  be  gradually 
increased  in  amount,  the  eliminative  or  selective 
process,  if  discriminate,  consistent,  and  sustained, 
will  work    towards    the     establishment    of    new 
adaptations  and  new  species.    Natural  Selection  is 
Nature's  process  of  singling  and  sifting  for  parent- 
hood by  the  discriminate  elimination  of  the  relatively 
less  fit  to  the  given  conditions. 

Take,  in  the  meantime,  just  one  illustration. 
In  Dublin  Bay  there  is  a  sandy  island,  about 
120  years  old.  It  is  frequented  by  a  light-coloured 


WHAT   WE    OWE   TO   DARWIN  17 

variety  of  mouse  which  burrows  in  the  sand. 
It  seems  reasonable  to  interpret  the  prevalence 
of  this  inconspicuous  sand-coloured  variety  as 
due  to  the  elimination  of  the  ordinary  darker 
mice  by  birds  of  prey. 

Wallace  asks  the  interesting  question :  Why, 
after  many  had  failed,  did  Darwin  and  he  find 
the  same  solution  of  the  riddle  of  progress,  namely, 
in  Natural  Selection?  He  points  out  that  they 
had  certain  experiences  in  common  :  (1)  as  ardent 
beetle-hunters  from  their  youth  up,  they  were  both 
accustomed  to  study  minute  details  and  varieties, 
and  they  thus  had  a  trained  eye  for  individualities ; 
(2)  they  both  had  a  speculative  turn  of  mind,  and 
were  fond  of  trying  solutions ;  (3)  they  both  enjoyed 
the  wealth  of  impressions  that  travel  gives,  and  the 
boon  of  solitude  and  quiet  in  which  to  "  attend 
their  minds  unto  "  the  problem  that  "  haunted  " 
them  ;  and  (4)  both  had  read  Malthus.  Perhaps 
one  might  add  that  both  had  realised  the  selective 
processes  implied  in  the  keen  competitive  con- 
ditions of  their  time. 

(V)  VINDICATION  OF  THE  EVOLUTION  IDEA. — 
What  do  we  owe  to  Darwin  ?  The  first  successful 
vindication  of  the  evolution  idea.  It  was  not 
his  own,  nor  was  he  its  first  champion,  yet  we 
always,  and  rightly,  think  of  Darwin  and  the 
Doctrine  of  Descent  together.  He  made  it  current 
coin  of.  the  intellectual  realm.  He  made  the 
nations  "  think  in  terms  of  evolution." 

The  central  idea  of  evolution  is  that  the  present 
is  the  child  of  the  past  and  the  parent  of  the 
future.  It  is  the  idea  of  progressive  change  from 
phase  to  phase  without  loss  of  continuity.  A 
process  of  Becoming  leads  to  a  new  phase  of 

2 


18         DARWINISM   AND   HUMAN   LIFE 

Being — whether  in  solar  systems  or  in  social 
institutions  or  in  living  creatures.  But  in  the 
first  the  continuity  is  sustained  in  identity  of 
substance,  in  the  second  by  tradition  and  social 
registration,  and  in  the  third  by  the  hereditary 
linkage  of  successive  generations. 

"  Stated  concretely,  in  regard  to  living  creatures, 
the  general  doctrine  of  descent  suggests,  as  we 
all  know,  that  the  plants  and  animals  now  around 
us  are  the  results  of  natural  processes  working 
throughout  the  ages;  that  the  forms  we  see  are 
the  lineal  descendants  of  ancestors  on  the  whole 
somewhat  simpler,  that  these  are  descended  from 
yet  simpler  forms,  and  so  on  backward,  till  we 
lose  our  clue  in  the  unknown — but  doubtless 
momentous — vital  events  of  pre-Cambrian  ages, 
or,  in  other  words,  in  the  thick  mist  of  life's 
beginnings/*  * 

"  As  hi  the  development  of  a  fugue,"  Samuel 
Butler  says,  "  where,  when  the  subject  and  counter- 
subject  have  been  announced,  there  must  thence- 
forth be  nothing  new,  and  yet  all  must  be  new, 
so  throughout  organic  nature — which  is  a  fugue 
developed  to  great  length  from  a  very  simple 
subject — everything  is  linked  on  to  and  grows 
out  of  that  which  comes  next  to  it  in  order." 

The  evolution  idea  is  not  only  essentially  simple, 
it  is  also  very  ancient.  It  is  as  old  as  Aristotle — 
and  older.  It  is  perhaps  as  old  as  clear  thinking, 
which  we  may  date  from  the  unknown  time  when 
man  discovered  the  year,  with  its  marvellous 
object-lesson  of  recurrent  sequences,  and  realised 
that  his  race  had  a  history.  Whatever  may  have 

1  "  The  Study  of  Animal  Life,"  by  J.  Arthur  Thomson.  (Murray, 
London.) 


WHAT   WE    OWE   TO    DARWIN  19 

been  its  origin,  the  idea  was  familiar  to  several 
of  the  ancient  Greek  philosophers,  as  it  was  to 
Hume  and  Kant;  it  fired  the  imagination  of 
Lucretius  and  linked  him  to  Goethe ;  it  persisted 
through  the  ages  of  other  than  scientific  pre- 
occupation ;  it  became  a  concrete  theory  of  the 
transformation  of  species  in  the  hands  of  the 
pioneers  of  modern  biology — such  as  Buff  on, 
Lamarck,  Erasmus  Darwin,  and  Treviranus ;  and 
it  became  current  intellectual  coin  when  Charles 
Darwin,  Alfred  Kussel  Wallace,  Herbert  Spencer, 
Huxley,  and  Haeckel,  with  united  but  varied 
achievements,  won  the  conviction  of  most  thought- 
ful men. 

THE  EVOLUTION  THEORY  A  MODAL  INTERPRE- 
TATION.— It  must  be  carefully  noted  that  the 
general  idea  of  organic  evolution  is  a  modal  inter- 
pretation of  the  history  of  the  animate  world.  It 
suggests  the  mode  by  which  organisms  have  come 
to  be  as  they  are.  It  says  that  the  mode  is  scien- 
tifically decipherable,  and  is  comparable  to  what 
we  see  going  on  in  the  origin  of  new  breeds  of 
pigeons  or  new  varieties  of  wheat.  But  what 
other  view  is  there  ?  We  do  not  know  of  any 
other  scientific  view,  and  the  only  alternative  is 
to  maintain  that  the  mode  of  origin  of  the  various 
kinds  of  living  creatures  is  undecipherable  scien- 
tifically, and  cannot  be  formulated  except  in 
transcendental  terms,  such  as  Creation.  The 
general  view  when  Darwin  published  the  "  Origin 
of  Species  "  was  Creationist,  or,  if  the  naturalist 
fought  shy  of  such  words,  the  Linnaean  dogma 
of  the  Fixity  of  Species  was  accepted  and  the 
question  of  origin  was  regarded  as  hopeless. 

Much  will  be  gained  if  we  clearly  understand 


20         DARWINISM   AND   HUMAN   LIFE 

that  the  theory  of  evolution  suggests  a  modal 
interpretation  within  the  scientific  universe  of 
discourse,  while  the  other  view  gives  up  even 
the  possibility  of  scientific  re-description,  and 
suggests  a  transcendental  formula  as  alone  possible. 
It  is  quite  certain  that  there  is  no  manner  of 
use  in  pitting  a  scientific  formula  against  a  trans- 
cendental one :  that  always  means  a  false  anti- 
thesis and  intellectual  fog.  They  are  incom- 
mensurables.  The  true  antithesis  is  between  a 
scientific  interpretation  and  maintaining  that  it 
is  impossible  to  give  one. 

There  is  an  intricate,  beautiful,  rational  pattern 
before  us  in  nature :  are  we  to  think  of  it  as  woven, 
thread  by  thread,  by  invisible  hands  in  a  way 
past  finding  out  scientifically',  or  was  there  so 
much  mind  put  into  the  original  institution  of 
things — an  apparently  simple  loom — that  thence- 
forth the  web  has  been  worked  out  automatically 
in  a  manner  that  admits  of  scientific  formulation  ? 
When  we  finally  discover  that  the  doctrine  of 
descent  and  all  the  theories  of  evolution  do  not 
fundamentally  explain  what  they  formulate,1  we 

1  This  expresses  the  common  view  that  science  is  re-description 
in  "  simpler  terms  " — which,  however,  are  not  themselves  "  ex- 
plained." In  regard  to  complexities  such  as  development  and 
behaviour  we  formulate  sequences,  but  we  cannot  flatter  ourselves 
that  our  ^notations  are  more  than  symbols  of  the  realities.  In 
his  "  L'Evolution  Cr6atrice,"  Prof.  Henri  Bergson  states  this 
position  (which  he  does  not  hold)  in  the  following  sentence  : 
"  Ce  n'est  plus  la  realit6  meme,  dit-elle,  qu'elle  recomposera,  mais 
seulement  une  imitation  du  reel,  ou  plutdt,  une  image  symbolique  ; 
1'essence  des  choses  nous  £chappe  et  nous  6chappera  toujours,  nous 
nous  mouvons  parmi  des  relations,  1'absolu  n'est  pas  de  notre 
ressort,  arretons-nous  devant  1'Inconnaissable."  For  an  exposition 
of  this  scientific  position  see  "  The  Bible  of  Nature,"  by  J.  Arthur 
Thomson  (1908). 


WHAT   WE    OWE   TO    DARWIN  21 

shall  be  able,  perhaps,  to  return  to  the  transcen- 
dental formula  with  intelligence. 

In  regard  to  the  proposition  that  science  offers 
not  explanations  but  formulations,  it  is  important 
to  bear  in  mind  (1)  that  the  biologist,  for  instance, 
postulates  simple  living  creatures  with  which 
to  start  his  story  of  evolution ;  (2)  that  he  also 
takes  for  granted  throughout  the  organism's 
power  of  varying  and  trading  with  time ;  (3) 
that  he  does  not  account,  as  yet,  for  the  "  big 
lifts  "  in  the  process  of  evolution,  or  for  the  direc- 
tion in  which  the  tree  has  grown  (vertically,  so 
to  speak,  as  well  as  horizontally) — a  direction 
which  gives  the  whole  process  greater  significance ; 
and  (4)  that  the  biologist's  causal  equation  is  not 
like  those  of  mechanics,  where  causa  aequat  effectum. 
Bergson  distinguishes  (a)  a  cause  acting  par 
impulsion,  as  when  one  billiard-ball  strikes  an- 
other (where  the  quantity  and  quality  of  the 
effect  vary  with  the  quantity  and  quality  of 
the  cause) ;  (6)  a  cause  acting  par  delanchement, 
as  when  a  spark  makes  the  powder  explode  (where 
the  invariable  effect  has  no  relation  to  the  quantity 
and  quality  of  the  cause) ;  and  (c)  a  cause  acting 
par  deroulement,  as  when  the  spring  which 
works  the  gramophone  unrolls  the  tune  on  the 
cylinder  (where  the  quantity  of  the  effect  is  pro- 
portionate to  the  quantity  of  the  cause).  In  the 
first  case  only  does  the  cause  explain  the  effect, 
but  living  is  not  such  an  effect. 

DARWIN'S  ARGUMENT.— What  did  Darwin  real*11" 
do  in  regard  to  the  general  doctrine  of  orpaams 
evolution  ?  He  showed  that  it  rationalist0?6" 
whole  outlook.  He  took  a  wide  sweep  .j:o  W** 
as  they  are  and  showed  that  they  a^7  smal1  ves" 


22         DARWINISM   AND    HUMAN    LIFE 

lutionist  interpretation.  There  are  no  locks  which 
its  key  does  not  fit.  As  there  is  often  misunder- 
standing in  regard  to  the  so-called  "  evidences  of 
evolution,"  we  must  note  that  Darwin's  magistral 
work  was  not  of  the  nature  of  an  induction  leading 
up  to  the  doctrine  of  descent  as  its  conclusion. 
It  was  a  deductive  vindication  of  the  doctrine 
that  he  gave  us — "  a  cumulative  justification 
showing  how  well  the  formula  fits  a  vast  series  of 
facts."  We  cannot  agree  with  the  statement 
that  Darwin  proved  in  1859  what  Lamarck  had 
only  suggested  fifty  years  before,1  for  there  is  no 
logical  proof  of  the  doctrine  of  descent.  It  must 
be  allowed,  however,  that  Darwin's  illustrations — 
what  some  would  call  his  cumulative  evidence — 
were  so  carefully  chosen  that  they  left  few  openings 
for  effective  criticism.  The  basis  of  fact  which 
the  formula  was  shown  to  fit  was  solid,  broad,  and 
representative. 

(a)  Darwin  pointed  to  the  evolution  which  is 
going  on  in  domesticated  animals,  such  as  sheep 
and  cattle,  and  in  cultivated  plants,  such  as 
cabbages  and  apples,  and  used  the  argument :  If 
Man  has  been  instrumental  in  fixing  all  these 
varieties  in  a  short  time,  what  may  not  Nature 
have  effected  in  a  very  long  time  ?  This  line  of 
argument  has  been  greatly  strengthened  of  recent 
years  by  cases  like  De  Vries's  mutations  of  the 
Evening  Primrose  ((Enothera  lamarckiana). 
t  (6)  There  is  significance  in  the  broad  fact  that 
!'*•  is  possible  to  arrange  the  animal  kingdom  in 
nousrt"o visional  genealogical  tree,  showing  stages 
of  this'sci^essiv6  organisation  from  lower  to  higher 

Thomson  (I9c.  «Philosophie  Zoologique"  was  published  in  1809, 
^  born 


WHAT   WE    OWE   TO    DARWIN  23 

forms.  When  we  take  a  particular  group  of 
animals  it  is  often  possible  to  draw  that  branch 
of  the  genealogical  tree  with  a  firmer  hand,  for 
it  is  the  mutual  relations  of  the  large  series  which 
are  so  difficult.  From  the  actual  classification  of 
organisms,  from  the  peculiar  way  in  which  the 
categories  are  related  one  within  the  other — 
species,  genera,  families,  orders,  classes — we  get 
an  impression  of  affiliation  which  we  do  not  get 
from  a  classification  of  rocks  or  other  inanimate 
objects. 

(c)  Darwin   attached  great  importance   to  the 
anatomical  evidence  of  adherence  to  general  type 
in  spite  of  the  most  manifold  diversity  in  external 
form.    If  we  take,  for  instance,  a  series  of  fore- 
limbs  among  Vertebrates — the  arm  of  a  frog,  the 
paddle  of  a  turtle,  the  wing  of  a  bird,  the  fore-leg 
of  a  horse,  the  flipper  of  a  whale,  the  wing  of  a 
bat,  the  arm  of  man — we  find  a  detailed  homology 
not  only  as  regards  the  bones,   but  as  regards 
muscles,  nerves,  and  blood-vessels.    It  is  difficult 
to   suggest   any   interpretation   except   that   the 
resemblance  is  due  to  relationship.    As  Darwin 
said :    "  How  inexplicable  is  the  similar  pattern 
of  the  hand  of  a  man,  the  foot  of  a  dog,  the  wing 
of  a  bat,  the  flipper  of  a  seal,  on  the  doctrine  of 
independent  acts  of  creation  !    How  simply  ex- 
plained on  the  principle  of  the  natural  selection 
of  successive  slight  variations  in  the   diverging 
descendants  from  a  single  progenitor  !  " 

(d)  Darwin   made   a   good   case   out   of    rudi- 
mentary or  vestigial  organs — the  dwindling  remains 
of  structures  which  were  presumably  well  developed 
in   ancestral   forms.     Cetaceans   have   no   visible 
hind-limbs,  but  many  show  relatively  small  ves- 


24         DARWINISM  AND    HUMAN   LIFE 

tiges  buried  deep  below  the  surface.  The  whale- 
bone whale  has  two  sets  of  teeth  which  never  cut 
the  gum,  their  place  being  taken  by  baleen  plates. 
The  New  Zealand  Kiwi  has  minute  traces  of  wings, 
the  limbless  slow-worm  has  a  rudimentary  pectoral 
girdle,  man  has  scores  of  vestiges,  such  as  the 
third  eyelid  or  the  ear-moving  muscles.  Darwin 
compared  these  vestiges  to  the  unsounded  letters 
in  many  words,  such  as  the  "  o "  in  leopard, 
the  "  b  "  in  doubt,  the  "  g  "  in  reign,  which  are 
quite  functionless,  but  tell  us  something  about 
the  history  of  the  words. 

(e)  It  is  a  simple  but  eloquent  fact  that  the 
geological  record  in  the  fossil-bearing  rocks  shows 
the  gradual  appearance  of  higher  and  higher 
forms.  At  a  certain  stage  in  the  history  of  the 
earth  all  the  animals  were  Invertebrates ;  then 
fishes  appeared,  then  amphibians,  then  reptiles, 
then  birds  and  mammals.  As  the  ages  have 
passed,  life  has  been  slowly  creeping  upwards. 
The  rock-record  corresponds  in  its  sequences 
with  those  deducible  from  comparative  anatomy 
and  embryology. 

Furthermore,  the  rock-record  reveals  quite  a 
number  of  connecting  links,  such  as  Archcvopteryx, 
the  oldest  known  bird,  which  has  some  distinctly 
reptilian  features,  and  a  larger  number  of  generalised 
types,  such  as  Phenacodus,  one  of  the  ancestors 
of  the  horse  lineage,  which  bind  together  several 
subsequently  specialised  families,  or  even  orders. 

In  certain  cases,  where  fossils  have  been  ob- 
tained from  successive  strata,  the  palaeontological 
series  is  wonderfully  complete,  and  the  various 
stages  in  the  evolution  of  tooth,  or  limb,  or  shell 
appear  like  the  stages  in  individual  development. 


WHAT    WE    OWE   TO    DARWIN  25 

Thus  there  is  convincing  completeness  in  the 
series  uniting  various  species  of  the  freshwater 
snails,  Paludina  and  Planorbis,  and  various  types 
of  Ammonites.  In  the  same  way  the  remarkable 
series  of  fossil  horses,  elephants,  and  crocodiles, 
are  either  records  of  pedigree  or  conundrums. 

(/)  The  development  of  the  individual  is  often 
in  some  measure  interpretable  as  a  condensed 
recapitulation  of  the  presumed  racial  evolution. 
The  individual,  as  Prof.  Milnes  Marshall  said, 
climbs  up  its  own  genealogical  tree.  Ontogeny 
tends  to  recapitulate  phylogeny,  especially  as 
regards  the  stages  passed  through  by  a  particular 
organ,  such  as  the  brain  or  the  heart.  In  their 
early  stages  there  is  a  remarkable  resemblance 
between  the  embryos  of  the  higher  Vertebrates: 
they  seem,  as  it  were,  to  travel  for  some  distance 
along  the  same  road  before  they  diverge  on  their 
several  paths.  Gill-slits  occur  in  the  development 
of  the  embryos  of  reptiles,  birds,  and  mammals, 
although  they  have  no  respiratory  significance  and 
are  not  of  any  use  at  all  except  that  one  seems  to 
become  the  Eustachian  tube  connecting  the  ear 
with  the  back  of  the  mouth.  The  young  tadpole 
of  the  frog  is  fish-like  in  many  details,  e.g.  as 
regards  the  heart  and  circulation.  The  very 
unsymmetrical  flat  fishes,  such  as  flounder  and 
sole,  pass  through  a  symmetrical  stage.  In  Fritz 
Miiller's  "  Facts  for  Darwin  "  the  recapitulation 
idea  was  applied  in  detail  to  Crustaceans,  and  it 
seems  impossible  to  understand  the  often  very 
circuitous  development  unless  it  has  an  historical 
significance. 

(g)  The  facts  of  geographical  distribution  in 
past  and  present  suggest  the  gradual  dispersal  of 


26         DARWINISM   AND   HUMAN   LIFE 

races  from  centres  where  they  had  their  original 
headquarters.  Peculiar  cases,  such  as  the  present- 
day  distribution  of  Camelidse,  or  the  fauna  of 
Australia,  or  the  population  of  oceanic  islands, 
readily  admit  of  evolutionist  interpretations. 

We  have  not  given  prominence  to  the  so-called 
evidences  of  evolution,  partly  because  they  have 
been  stated  so  often — e.g.  by  Romanes  and  by 
Mimes  Marshall — partly  because  none  of  the  so- 
called  evidence  is  in  itself  demonstrative  in  the 
strict  sense.  All  that  is  shown  is  that  the  formula 
fits  a  wide  and  representative  series  of  facts,  and 
enables  us  to  think  of  them  in  a  clear  and  rapid 
way.  What  can  be  securely  said  is  this,  that  all 
biological  facts  can  be  used  as  evidence  of  evolution 
if  we  know  enough  about  them,  and  there  are  no 
biological  facts  which  are  inconsistent  with  it, 
so  far  as  we  know. 

COMPARISON  OF  EVOLUTION  FORMULA  AND 
GRAVITATION  FORMULA. — Let  us  compare  the 
evolution  theory  with  one  of  the  great  physical 
generalisations — the  gravitation  formula.  Both 
are  simple  in  statement,  both  are  wide  as  the 
world  in  their  applicability.  We  are  aware  of 
no  facts  contradictory  to  either.  Furthermore, 
they  are  alike  in  this,  that  neither  proposes  any 
ultimate  explanation,  that  both  are  examples 
of  intellectual  shorthand,  of  thought-economising, 
descriptive  formulae.  We  do  not  know  why 
one  body  attracts  another  in  the  manner  which 
Newton  formulated ;  we  do  not  know  why 
life  should  have  its  power  of  slowly  creeping 
upwards.  It  has  been  pointed  out  that,  just  as 
Newton  started  with  gravitation  as  a  big  funda- 
mental fact,  so  Darwin  started  from  variation, 


WHAT   WE    OWE   TO    DARWIN  27 

and  that  both  left  their  fundamental  assumption 
from  experience  unexplained. 

But  there  is  this  difference  between  the  gravi- 
tation formula  and  the  evolution  idea,  that  the 
experimental  vindication  of  the  first  is  easy, 
while  that  of  the  second  is,  to  say  the  least,  ex- 
tremely difficult.  Whether  we  study  the  apples 
falling  in  the  orchard  or  the  planets  in  their  courses, 
we  can  continually  confirm  the  accuracy  of  the 
gravitation  formula,  to  which  two  centuries  have 
not  added  anything  essential,  from  which  two 
centuries  have  taken  nothing  away. 

But  the  evolution  doctrine  does  not  rest  on  a 
foundation  of  this  sort.  Like  wisdom,  it  is  justified 
of  its  children — by  half  a  century's  using — and 
to  speak  of  proving  it  is  to  misunderstand  it. 

Before  passing  from  the  general  idea  of  organic 
evolution  we  must  point  out  that  it  is  no  mere 
doctrine  of  the  schools,  but  an  important  human 
asset — of  practical  and  emotional,  as  well  as  of 
intellectual  value.  In  accepting  the  evolution 
idea  we  lose  no  small  part  of  its  virtue  if  we  do 
not  visualise  it,  if  we  do  not,  in  some  measure, 
image  the  relative  simplicity  of  life's  beginnings 
and  the  long  pageant  that  has  passed  in  gorgeous 
procession  over  the  earth  for  millions  of  years ; 
if  we  do  not  understand  that  evolution  is  going 
on  still  and  that  it  includes  us  and  our  doings  in 
its  sweep.1 

1  Emile  Ferriere  illustrates  the  theory  of  organic  evolution 
very  clearly  by  drawing  a  parallel  between  species  and  languages. 

A  language  may  have  many  varieties,  just  as  a  species  often 
has.  In  both  cases  there  is  evidence  of  slow  transformation  and 
of  demonstrable  pedigrees.  Changes  may  be  observed  in  actual 
occurrence  alike  in  languages  and  in  organisms.  It  is  possible 
in  both  to  distinguish  changes  arising  from  within  (intrinsic  varia- 


28         DARWINISM   AND   HUMAN   LIFE 

(VI)  THE  DESCENT  AND  ASCENT  OF  MAN. — 
What  do  we  owe  to  Darwin  ?  A  recognition  of 
man's  solidarity  with  the  rest  of  creation,  of  his 
affiliation  to  a  Simian  stock.  In  the  cumulative 
argument  of  the  "  Descent  of  Man,"  Darwin 
disclosed  the  rock  whence  he  was  hewn  and  the 
pit  whence  he  was  digged,  showing,  not  exactly 
that  "  man  sprang  from  a  monkey,"  as  the  vulgar 
idea  is,  but  that  man  and  anthropoid  apes  are 
collateral  branches  from  a  common  Primate  stock 
which  remains  hidden  in  obscurity. 

Darwin  gave  details  of  the  all-pervading  simi- 
litude of  structure  between  man  and  the  anthropoid 
apes,  to  which  the  researches  of  recent  years 
have  added  such  striking  items  as  a  sameness 
in  blood-reaction  to  Friedenthal's  test.  He  showed 
how  we  carry  about  with  us  a  museum  of  relics 
indicative  of  our  ancestry — a  museum  whose 
catalogue  now  amounts,  according  to  Wiedersheim, 
to  about  a  hundred  items.  The  anatomical  re- 
semblances between  adult  man  and  adult  apes 
are  associated  with  even  closer  resemblances  in 
the  embryos,  and  gain  additional  significance 
when  we  take  into  account  the  scanty  skeletal 
remains  of  primitive  man,  the  lower  races  of 
men,  and  the  occurrence  of  almost  sub-human 
types  occasionally  born  in  times  of  distress. 
The  affiliation  applies  to  mind  as  well  as 
body,  for  there  is  an  ever-growing  mass  of 

tions)  from  changes  imposed  from  without  (extrinsic  modifications). 
Young  stages  of  a  language  show  embryonic  features,  just  as 
languages  that  have  been  evolving  for  centuries  show  vestigial 
structures,  such  as  the  familiar  unsounded  letters  in  words.  There 
are  fossil  languages,  just  as  there  are  fossil  species.  Both  in 
languages  and  in  species  we  can  recognise  the  operation  of  selective 
processes  and  the  effect  of  isolation, 


WHAT   WE    OWE   TO   DARWIN  29 

facts  relating  to  peculiar  psychoses  in  child  and 
adult  which  we  must  recognise  as  vestigial  and 
recapitulatory.1 

Those  who  feel  a  repugnance  to  the  Darwinian 
conclusion  that  man  is  descended  from  a  humble 
Simian  ancestry  should  remember  the  marvellous 
ascent  in  each  individual  lifetime.  Neither  the 
dignity  nor  the  value  of  a  result  is  affected  by 
the  historical  conditions  of  its  becoming.  And 
if  man  is  separated  off  by  reason  (or  the  power  of 
conceptual  inference),  by  morality  (or  the  habit 
of  controlling  his  conduct  in  reference  to  ideals), 
by  the  possession  of  true  language  or  Logos,  and 
by  other  qualities  distinctively  human,  then  we 
must  increase  our  respect  for,  and  see  more  in, 
that  brute  creation  which  contained  the  potenti- 
ality of  all.  For  it  is  a  fundamental  idea  of 
evolution  that  there  is  nothing  in  the  end  which 
is  not  also  in  the  beginning. 

(VII)  LIBERATION  OP  INTELLIGENCE. — What  do 
we  owe  to  Darwin  ?  A  great  liberation  of  the  in- 
telligence. Like  Abraham  Lincoln,  who  was  born 
on  the  same  day  in  the  same  year,  Darwin  worked 
for  freedom,  though  perhaps  without  ever  thinking 
of  it.  As  Prof.  H.  E.  Crampton  has  said : 
"  The  '  Origin  of  Species '  has  proved  a  veritable 
Magna  Charta  of  intellectual  liberties,  for,  as 
no  other  single  document  before  or  since,  it  has 
released  the  thoughts  of  men  from  the  trammels 
of  unreasoned  conservatism  and  dogmatism." 
Speaking  of  his  first  impressions  of  the  "  Origin 

1  Prof.  Stanley  Hall  gives,  as  an  illustration,  "  the  new  psychology 
of  crime  and  criminals,  who  are  so  shot  through,  body  and  soul, 
with  atavisms  that  only  the  early  history  of  the  race  can  explain 
them." 


30         DARWINISM   AND   HUMAN   LIFE 

of  Species/'  Sir  Francis  Galton  has  told  us  that 
his  dominant  feeling  was  one  of  freedom. 

For  one  must  remember  that  Darwin  attacked 
a  whole  series  of  problems  which,  for  most  of 
his  contemporaries,  were  either  insoluble  mysteries 
or  a  preserve  for  transcendental  interpretation. 
"  Evolution,"  Prof.  Bateson  says,  "  is  a  process 
of  variation  and  heredity.  The  older  writers, 
though  they  had  some  vague  idea  that  it  must 
be  so,  did  not  study  variation  and  heredity. 
Darwin  did,  and  so  begat,  not  a  theory,  but  a 
science."  *  He  showed  that  the  deeper  mysteries 
of  life  were  in  a  measure  accessible  to  the  scientific 
method.  He  won  freedom  for  the  application  of 
the  evolution  formula  to  man  as  well  as  to  other 
creatures,  and  not  only  to  his  body,  but  to  his 
emotions  and  behaviour.  He  was  one  of  the 
founders  of  genetic  psychology,  which,  though 
still  hardly  above  the  ground,  is  destined  to 
make  for  the  growing  freedom  of  the  human 
spirit.  We  mean  not  merely  intellectual  freedom 
from  obscurity,  but  a  practical  freedom  as  well; 
for  in  regard  to  the  mind,  as  well  as  the  body, 
Darwin  set  a-going  a  kind  of  inquiry  into  individual 
development  and  racial  evolution,  into  variation 
and  heredity,  which  promises  to  give  us  a  firmer 
control  of  life.  We  are  only  beginning  to  realise 
that  the  truth  which  is  in  Darwinism  shares  with 
all  truth  the  power  of  making  us  free. 

Darwin  gave  men  confidence  in  the  interpre- 
tative value  of  the  evolution  formula,  which 
makes  the  present  less  obscure  by  throwing  on 
it  the  light  of  the  past,  and  every  one  knows  how 
the  interpretation  has  been  applied  to  mind, 

1  "  Darwin  and  Modern  Science,"  (1909),  p.  88. 


WHAT   WE    OWE   TO   DARWIN  31 

to  morals,  to  language,  to  art,  to  customs,  to 
religion.  Even  the  evolution  theory  has  had 
its  evolution,  and  is  still,  happily,  being  evolved. 

Of  the  wide  diffusion  of  the  evolutionary  way 
of  looking  at  things  which  Darwin  justified,  we 
give  a  single  example,  as  a  diagram  as  it  were. 
After  the  disaster  of  Koniggratz  the  Austrian 
Parliament  met  to  consider  what  steps  should 
be  taken  for  the  re-consolidation  of  the  monarchy, 
and  a  distinguished  member  of  the  Upper  House 
began  a  famous  speech  with  the  words,  "  The  first 
thing  we  have  to  consider  is :  Is  Charles  Darwin 
right,  or  is  he  not  ?  " — "  and  upon  the  Tightness  of 
Darwin's  theory  it  was  gravely  proposed  to  re- 
construct the  Austrian  monarchy." 1 

Darwin  once  expressed  satisfaction  that  he 
had  not  been  permitted  to  become  a  "  specialist "  ; 
it  is  hardly  too  much  to  say  that  there  is  no 
specialism  in  natural  science  which  he  has  left 
unaffected  by  his  influence. 

(VIII)  IDEAL  OF  SCIENTIFIC  MOOD  AND  METHOD. 
— What  do  we  owe  to  Darwin  ?  An  ideal  of 
the  scientific  mood  and  of  scientific  workmanship. 
As  it  will  be  a  long  time  before  Science  weeps,  like 
Alexander,  having  no  more  worlds  to  conquer, 
perhaps  this  ideal  is  not  the  least  of  Darwin's 
legacies.  If  we  can  follow  Darwin  in  the  spirit, 
not  necessarily  in  the  letter,  we  shall  not  go  far 
astray.  As  Prof.  T.  H.  Morgan  finely  says : 
"It  is  the  spirit  of  Darwinism,  not  its  formulae, 
that  we  proclaim  as  our  best  heritage."  For 
this  reason,  and  because  the  scientific  spirit  is  a 
big  fact  in  modern  life,  let  us  consider  the  features 

i  See  Sir  Archibald  Geikie's  Speech  at  the  Darwin-Wallace 
Celebration,  Linnean  Society  (July  1st,  1908),  p.  53. 


32         DARWINISM   AND   HUMAN   LIFE 

of  the  scientific  mood,  and  Darwin's  illustration 
of  them. 

In  his  stimulating  presidential  address  at  the 
meeting  of  the  British  Association  at  Dover  in 
1899,  Sir  Michael  Foster  discussed  the  distinctive 
features  of  the  scientific  spirit — of  which  he  was 
himself  a  fine  embodiment.  His  answer  was  that 
the  features  of  the  fruitful  scientific  mood  are 
in  the  main  three — truthfulness,  alertness,  and 
courage.  (1)  "The  seeker  after  truth  must  him- 
self be  truthful — truthful  with  the  truthfulness  of 
nature/'  (2)  "  He  must  be  alert  of  mind,  ever 
on  the  watch,  ready  at  once  to  lay  hold  of  Nature's 
hint,  however  small ;  to  listen  to  her  whisper, 
however  low."  (3)  "  Scientific  inquiry  has  need  of 
the  moral  quality  of  courage — not  so  much  the 
courage  which  helps  a  man  to  face  a  sudden 
difficulty,  as  the  courage  of  steadfast  endurance." 
To  the  objection  that  truthfulness,  alertness,  and 
courage  are  virtues  belonging  to  almost  every  one 
who  has  commanded  or  deserved  success,  Sir 
Michael  answered :  "  That  is  exactly  what  I 
would  desire  to  insist,  that  men  of  science  have 
no  peculiar  virtues,  no  special  powers.  They  are 
ordinary  men,  their  characters  are  common,  even 
commonplace.  Science,  as  Huxley  said,  is  organ- 
ised common  sense,  and  men  of  science  are  common 
men,  drilled  in  the  ways  of  common  sense." 

CHARACTERISTICS  OF  SCIENTIFIC  MOOD  :  PASSION 
AND  REVERENCE  FOR  FACTS. — But  let  us  consider 
the  scientific  mood  more  analytically.  The  first 
characteristic  of  the  scientific  mood  is  a  passion 
and  reverence  for  facts.  Long  ago  Bacon  said  : 
"We  should  accustom  ourselves  to  things  them- 
selves " ;  and  to  distinguish  between  appearance 


WHAT   WE    OWE   TO    DARWIN  33 

and  reality  is  part  of  the  unending  business  of 
science.  Faraday  said  that  the  scientific  investi- 
gator should  be  "not  a  respecter  of  persons,  but 
of  things."  It  was  Huxley  who  spoke  of  "that 
enthusiasm  for  truth,  that  fanaticism  of  veracity, 
which  is  a  greater  possession  than  much  learning  ; 
a  nobler  gift  than  the  power  of  increasing  know- 
ledge." Darwin  was  a  fine  illustration  of  this 
passion  for  facts  ;  there  have  been  few  naturalists 
more  careful  as  to  data.  He  began  collecting  facts 
in  regard  to  the  work  of  earthworms  when  a 
young  student  in  Edinburgh,  and  he  published 
his  fascinating  book  the  year  in  which  he  died. 
His  gardener  said :  "  He  moons  about  in  the 
garden,  and  I  have  seen  him  stand  doing  nothing 
before  a  flower  ten  minutes  at  a  time." 

SCIENTIFIC  CAUTION. — Following  from  the  pas- 
sion of  facts  is  a  second  characteristic  of  the 
scientific  mood,  namely,  cautiousness,  or  distrust 
of  finality  and  dogmatism  of  statement.  Prof. 
W.  K.  Brooks  says,  in  his  "  Foundations  of 
Zoology  "  :  "  The  hardest  of  intellectual  virtues 
is  philosophic  doubt,  and  the  mental  vice  to 
which  we  are  most  prone  is  our  tendency  to  believe 
that  lack  of  evidence  for  an  opinion  is  a  reason 
for  believing  something  else.  .  .  .  Suspended  judg- 
ment is  the  greatest  triumph  of  intellectual  dis- 
cipline." As  Huxley  said :  "  The  assertion  that 
outstrips  the  evidence  is  not  only  a  blunder  but 
a  crime."  As  Karl  Pearson  says  :  "  The  scientific 
man  has,  above  all  things,  to  strive  at  self-elimina- 
tion in  his  judgments,  to  provide  an  argument  which 
is  as  true  for  each  individual  mind  as  for  his 
own."  What  a  fine  temper  there  is  in  Darwin's 
statement — "  I  have  steadily  endeavoured  to 

3 


34         DARWINISM   AND    HUMAN   LIFE 

keep  my  mind  free  so  as  to  give  up  any  hypothesis, 
however  much  beloved — and  I  cannot  resist 
forming  one  on  every  subject — as  soon  as  facts  are 
shown  to  be  opposed  to  it."  "  I  had/'  he  says, 
"  during  many  years  followed  a  golden  rule,  namely, 
that  whenever  a  published  fact,  a  new  observation 
or  thought  came  across  me,  which  was  opposed 
to  my  general  results,  to  make  a  memorandum 
of  it  without  fail,  and  at  once ;  for  I  had  found, 
by  experience,  that  such  facts  and  thoughts  were  far 
more  apt  to  escape  from  the  memory  than  favourable 
ones/'  Let  us  remember  how  Darwin  opened  his  first 
note-book  in  1837,  conceived  the  idea  of  natural 
selection  in  1838,  sent  a  sketch  of  the  theory  to 
Hooker  in  1844,  read  his  joint-paper  with  Wallace 
in  1858,  and  published  "  The  Origin  of  Species  "  in 
1859.  These  dates  are  eloquent.  It  is  interesting 
to  notice  that  Wallace  wrote  his  sketch  in  a  week 
— the  thought-stream  of  his  fevered  brain  in  spate. 
CLEARNESS  OF  VISION. — A  third  characteristic 
of  the  scientific  mood  is  dislike  of  obscurities,  of 
blurred  vision,  of  fogginess.  Ignorance  in  itself 
is  no  particular  reproach,  if  it  is  not  carried  too 
far,  but  it  is  essential  to  know  when  we  know 
and  when  we  do  not.  The  mole  has  a  strange 
half-finished  lens,  which  is  physically  incapable 
of  throwing  a  precise  image  on  the  retina.  If 
there  is  any  image,  it  must  be  a  blurred  tangle 
of  lines.  In  our  busy  lives  we  tend  to  acquire 
mole-like  lenses  in  regard  to  particular  orders  of 
facts ;  we  see  certain  things  clearly,  others  are 
blurs ;  but  the  scientific  mood  is  in  continual 
protest  against  obscurities,  insisting  upon  lucidity. 
One  of  Bacon's  most  historically  true  aphorisms 
declares  "  Truth  to  emerge  sooner  from  error 


WHAT    WE    OWE   TO    DARWIN  35 

than  from  confusion."  Now  we  may  claim  for 
Darwin  the  quality  of  definiteness  and  lucidity. 
He  was  convinced  of  the  efficacy  of  natural 
selection,  and  his  exposition,  though  rarely  elegant, 
is  always  clear.  He  did  not  understand  how 
variations  in  the  direction  of  fitness  arose,  and 
he  said  so.  His  yea  was  yea,  and  his  nay,  nay. 

SENSE  OF  INTERRELATIONS. — A  fourth  charac- 
teristic of  the  scientific  mood  is  a  sense  of  the 
interrelations  of  things.  The  realisation  of  Nature 
as  a  great  interconnected  system  is,  indeed,  one 
of  the  ends  of  science ;  to  be  on  the  outlook  for 
interrelations  is  diagnostic  of  the  scientific  mood. 
We  have  seen  how  Darwin  had  the  vision  of  the 
web  of  life  with  pre-eminent  vividness. 

DARWIN'S  METHOD  OF  WORKING. — As  to  Dar- 
win's method  of  working,  he  tells  us  himself  three 
things  :  (1)  that  he  had  from  his  earliest  youth 
a  desire  to  explain  things,  and  that  he  could  not 
resist  forming  an  hypothesis  on  every  subject; 
(2)  that  he  accumulated  large  collections  of  facts 
and  tried  to  formulate  them  in  a  general  law; 
and  (3)  that  he  sought  to  anticipate  all  possible 
objections  to  his  conclusion.  In  short,  he  was  a 
deductive-inductive  philosopher. 

In  speaking  of  Darwin's  services,  Romanes 
said :  "A  true  scientific  judgment  consists  in 
giving  a  free  rein  to  speculation  on  the  one  hand, 
while  holding  ready  the  brake  of  verification  with 
the  other.  Now  it  is  just  because  Darwin  did 
both  these  things  with  so  admirable  a  judgment 
that  he  gave  to  the  world  of  natural  history  so 
good  a  lesson  as  to  the  most  effective  way  of 
driving  the  chariot  of  science."1 

„     i  "Darwin  and  After  Darwin"  (1897),  vol.  i.  p.  7. 


36         DARWINISM   AND    HUMAN   LIFE 

Prof.  Karl  Pearson  says,  in  his  "  Grammar  of 
Science,"  that  the  scientific  method  is  marked  by 
the  following  features  :  "  (a)  careful  and  accurate 
classification  of  facts  and  observation  of  their 
correlation  and  sequence ;  (6)  the  discovery  of 
scientific  laws  by  aid  of  the  creative  imagination ; 
and  (c)  self-criticism  and  the  final  touchstone  of 
equal  validity  for  all  normally  constituted  minds." 
The  writer  had  Darwin  as  well  as  Newton  in 
mind  when  he  framed  this  useful  definition. 

DARWIN  ON  HIS  OWN  SUCCESS. — No  one  who  has 
read  Darwin's  "  Autobiography  "  can  forget  how 
he  himself  deals  with  the  question  of  his  success. 
"  My  success  as  a  man  of  science,  whatever  this 
may  have  amounted  to,  has  been  determined,  as 
far  as  I  can  judge,  by  complex  and  diversified 
mental  qualities  and  conditions.  Of  these,  the 
most  important  have  been — the  love  of  science, 
unbounded  patience  in  long  reflecting  over  any 
subject,  industry  in  observing  and  collecting  facts, 
and  a  fair  share  of  invention  as  well  as  of  common 
sense.  With  such  moderate  abilities  as  I  possess, 
it  is  truly  surprising  that  I  should  have  influenced 
to  a  considerable  extent  the  belief  of  scientific 
men  on  some  important  points." 

DARWIN'S  ACHIEVEMENTS. — Let  us  turn  from 
that  humility  of  greatness  once  more  to  the  actual 
achievement.  The  idea  of  organic  evolution,  older 
than  Aristotle,  slowly  developed  from  the  stage 
of  suggestion  to  the  stage  of  verification,  and 
the  first  convincing  verification  was  Darwin's ; 
from  being  an  a  priori  anticipation  it  has  become 
a  detailed  interpretation  of  nature,  and  Darwin 
is  still  the  chief  interpreter ;  from  being  a  modal 
interpretation  of  the  manner  in  which  living 


WHAT    WE    OWE   TO    DARWIN  37 

creatures  have  come  to  be,  it  has  advanced  to  the 
rank  of  a  causal  theory,  the  most  convincing  part 
of  which  men  will  never  cease  to  call  Darwinism. 

In  referring  to  Darwin's  services,  Huxley  wrote  : 
"  Whatever  be  the  ultimate  verdict  of  posterity 
upon  this  or  that  opinion  which  Mr.  Darwin  pro- 
pounded ;  whatever  adumbrations  or  anticipations 
of  his  doctrines  may  be  found  in  the  writings  of 
his  predecessors ;  the  broad  fact  remains  that, 
since  the  publication,  and  by  reason  of  the  publica- 
tion, of  '  The  Origin  of  Species  '  the  fundamental 
conceptions  and  the  aims  of  students  of  living 
nature  have  been  completely  changed.  .  .  .  But 
the  impulse  thus  given  to  scientific  thought  rapidly 
spread  beyond  the  ordinarily  recognised  limits 
of  biology.  Psychology,  ethics,  cosmology  were 
stirred  to  their  foundations,  and  '  The  Origin  of 
Species '  proved  itself  the  fixed  point  which  the 
general  doctrine  needed  in  order  to  move  the 
world." 

CO-OPERATING  INFLUENCES. — To  understand  how 
all  this  came  about  we  must  get  beyond  the  person- 
ality of  Darwin.  We  must  shake  ourselves  free 
from  all  creationist  appreciations  of  Darwin  and 
Darwinism ;  we  must  recognise  the  services  of 
pioneers  who  helped  to  make  the  time  ripe — 
notably,  for  instance,  Robert  Chambers,  whose 
work  has  seldom  been  adequately  appreciated ; 
we  must  inquire  into  the  acceptance  of  evolutionary 
conceptions  in  regard  to  other  than  biological 
orders  of  facts ;  we  must  realise  how  the  growing 
success  of  scientific  interpretation  along  other 
lines  gave  confidence  to  those  who  refused  to 
admit  that  there  was  any  domain  from  which 
science  could  be  excluded  as  a  trespasser ;  we 


38         DARWINISM    AND    HUMAN    LIFE 

must  take  account  of  the  development  of  philo- 
sophical thought — for  instance  in  Herder,  Kant, 
and  Hegel ;  we  should  also,  if  we  are  wise  enough, 
consider  social  changes.  In  short,  we  must  abandon 
the  idea  that  we  can  understand  a  great  step 
like  the  acceptance  of  the  evolutionist  outlook 
without  getting  beyond  the  individual  prophet, 
without  associating  his  work  with  contemporary 
evolution  in  other  departments  of  activity.  The 
man  and  the  moment  must  agree,  and,  as  Professor 
R.  M.  Wenley  says  in  this  very  connection,  "  genius 
rarely  achieves  supremacy  without  the  co-operant 
'  social  mind/  " 

There  is  a  risk  of  attaching  too  much  importance 
to  the  force  of  individual  effort  on  the  one  hand, 
and  to  the  ripening  of  public  opinion  on  the  other. 
The  storm  of  opposition  roused  by  the  publication 
of  "  The  Origin  of  Species  "  shows  how  far  the 
time  was  from  being  ripe.  To  say,  as  Samuel 
Butler  said,  "  Buffon  planted,  Erasmus  Darwin  and 
Lamarck  watered,  but  it  was  Mr.  Darwin  who 
said  '  That  fruit  is  ripe '  and  shook  it  into  his 
lap/'  seems  to  us  as  wilful  a  perversion  of  historical 
fact  as  that  other  statement  by  the  same  ingenious 
and  often  well-advised  critic,  "  Darwin  was  heir  to 
a  discredited  truth,  and  left  behind  him  an  ac- 
credited fallacy."  Much  more  accurate  is  Huxley's 
fine  pronouncement * :  "  None  have  fought  better, 
and  none  have  been  more  fortunate,  than  Charles 
Darwin.  He  found  a  great  truth  trodden  underfoot, 
reviled  by  bigots,  and  ridiculed  by  all  the  world ;  he 
lived  long  enough  to  see  it,  chiefly  by  his  own  efforts, 
irrefragably  established  in  science."  That  the  time 
was  far  from  ripe  is  shown  by  Darwin's  foreboding : 

i  "  Darwiniana,"  p.  247. 


WHAT    WE    OWE    TO    DARWIN  39 

"  When  my  notes  are  published  I  shall  fall  infinitely 
low  in  the  opinion  of  all  sound  naturalists ;  so  this 
is  my  prospect  for  the  future."  That  the  time 
was  far  from  ripe  is  well  shown  in  a  passage  in  the 
second  volume  of  Buckle's  "  History  of  Civilisa- 
tion," which  was  published  two  years  after  "  The 
Origin  of  Species  " :  "  We  are  in  that  predicament 
that  our  facts  have  outstripped  our  knowledge, 
and  are  now  encumbering  its  march.  The  publica- 
tions of  our  scientific  institutions,  and  of  our 
scientific  authors,  overflow  with  minute  and 
countless  details,  which  perplex  the  judgment, 
and  which  no  memory  can  retain.  In  vain  do 
we  demand  that  they  should  be  generalised  and 
reduced  into  order.  Instead  of  that,  the  heap 
continues  to  swell.  We  want  ideas,  and  we  get 
more  facts.  We  hear  constantly  of  what  nature 
is  doing,  but  we  rarely  hear  of  what  man  is  thinking. 
Owing  to  the  indefatigable  industry  of  this  and 
the  preceding  century,  we  are  in  possession  of  a 
huge  and  incoherent  mass  of  observations,  which 
have  been  stored  up  with  great  care,  but  which, 
until  they  are  connected  by  some  presiding  idea, 
will  be  utterly  useless."  And  yet  one  of  the 
greatest  of  generalisations,  one  of  the  most  powerful 
of  presiding  ideas,  was  awaiting  Buckle's  recogni- 
tion. It  was  eminently  characteristic  of  Darwin 
that  the  accumulation  of  facts  was  to  him  not 
an  end  but  a  means  to  an  end. 

PARTICULAR  REASONS  FOR  DARWIN'S  SUCCESS. — 
We  must  grant  that  the  intellectual  temper  of 
the  time  was  changing,  that  in  various  departments 
men  were  becoming  familiar  with  the  historical 
method — the  first  step  to  becoming  evolutionists, 
that  the  genetic  view  of  nature  was  insinuating 


40         DARWINISM   AND   HUMAN    LIFE 

itself  like  a  slow  incoming  tide  in  men's  minds, 
and  that  the  scientific  spirit  had  ripened  since 
the  days  when  Cuvier  laughed  Lamarck  out  of 
court,  but  we  must  still  ask,  more  personally,  how 
it  was  that  Darwin  succeeded  so  well.  There  are 
several  answers. 

Because,  in  the  first  place,  he  had  clear  visions — 
pensees  de  la  jeunesse,  executees  par  I'dge  mur — 
which  a  University  curriculum  had  not  made 
impossible,  which  the  Beagle  voyage — a  Columbus 
voyage  that  discovered  a  new  world — had  made 
vivid,  which  an  unrivalled  British  doggedness 
made  real — visions  of  the  web  of  life,  of  the  fountain 
of  change  within  the  organism,  of  the  struggle  for 
existence,  of  discriminate  winnowing  or  selection, 
and  of  the  spreading  genealogical  tree. 

Because,  in  the  second  place,  he  put  so  much 
grit  into  the  verification  of  his  visions,  forcing 
them  to  the  proof  in  an  argument  which  is,  of 
its  kind — direct  demonstration  being  out  of  the 
question — quite  unequalled. 

Because,  in  the  third  place,  he  broke  down 
the  opposition  which  the  most  scientific  had  felt 
to  the  seductive  modal  formula  of  evolution,  by 
bringing  forward  a  more  plausible  theory  of  the 
process  than  had  been  previously  suggested.  Nor 
can  one  forget,  since  questions  of  this  magnitude 
are  human  and  not  merely  academic,  that  Darwin 
wrote,  of  his  condescension,  so  that  all  men  could 
understand. 

As  Mr.  Arthur  Balfour  recently  said :  "  Charles 
Darwin's  performances  have  now  become  part 
of  the  common  intellectual  inheritance  of  every 
man  of  education,  wherever  he  lives  or  whatever 
his  occupation  or  trade  in  life.  To  him  we  trace, 


WHAT    WE    OWE   TO   DARWIN  41 

in  the  main,  the  view  which  has  affected,  not 
merely  our  ideas  of  the  development  of  living 
organisms,  but  our  ideas  upon  politics,  upon 
sociology,  ideas  which  cover  the  whole  domain  of 
human  terrestrial  activity.  He  is  the  fount  and 
origin,  and  he  will  stand  for  all  time  as  the  man 
who  has  made  this  great,  and,  as  I  think,  beneficent 
revolution  in  the  mode  in  which  educated  men 
can  see  the  history,  not  merely  of  their  own  institu- 
tions, not  merely  of  their  own  race,  but  of 
everything  which  has  that  unexplained  attribute 
of  life,  everything  that  lives  on  the  surface  of 
the  globe  or  within  the  depths  of  the  ocean/'1 

In  any  case,  we  must  agree  with  what  Huxley 
says  of  Darwin  :  "  It  is  only  by  pursuing  his 
method,  by  that  wonderful  single-mindedness, 
devotion  to  truth,  readiness  to  sacrifice  all  things 
for  the  advance  of  definite  knowledge,  that 
we  can  hope  to  come  any  nearer  than  we  are 
at  present  to  the  truths  which  he  struggled  to 
attain/' 

Darwin  was  no  metaphysician ;  he  always  kept 
very  close  to  earth — which  is  half  the  secret  of 
the  persistent  strength  of  his  teaching.  For  this 
reason,  most  appropriately,  Prof.  R.  M.  Wenley 
ended  a  very  suggestive  address 2  on  Darwin  by 
quoting,  in  reference  to  Darwin's  services,  the 
fine  words  of  a  Scottish  poet : 

Man's  thought  is  like  Antaeus,  and  must  be 
Touched  to  the  ground  of  Nature  to  regain 
Fresh  force,  new  impulse,  else  it  would  remain 
Dead  in  the  grip  of  strong  Authority. 

1  Nature,  July  1st,  1909. 

«  Popular  Science  Monthly  (1909),  voL  Ixxiv.  p.  395. 


42         DARWINISM   AND    HUMAN    LIFE 

But,  once  thereon  reset,  'tis  like  a  tree, 
Sap-swollen  in  spring-time  :   bonds  may  not  restrain ; 
Nor  weight  repress ;   its  rootlets  rend  in  twain 
Dead  stones  and  walls  and  rocks  resistlessly. 

Thine,  then,  it  was  to  touch  dead  thoughts  to  earth, 
Till  of  old  dreams  sprang  new  philosophies, 
From  visions  systems,  and  beneath  thy  spell 
Swiftly  uprose,  like  magic  palaces, — 
Thyself  half-conscious  only  of  thy  worth — 
Calm  priest  of  a  tremendous  oracle  ! 


CHAPTER   II 
THE  WEB   OF  LIFE 


43 


CHAPTEE   II 

THE   WEB   OF  LIFE 

Correlation  of  Organisms  as  well  as  Correlation  of  Organs — What 
the  Metaphor  of  "  The  Web  of  Life  "  suggests — Dependence  of 
Living  Creatures  upon  their  Surroundings — Nutritive  Chains 
— Nexus  between  Mud  and  Clear  Thinking — Correlation 
between  Catches  of  Mackerel  and  Amount  of  Spring  Sunshine 
— Nutritive  Chains  in  the  Deep  Sea — Dependence  of  one 
Organism  on  another  for  the  Continuance  of  the  Species 
— Darwin's  Instance  of  the  Connection  between  Cats  and 
Clover — Scattering  of  Seeds — Interrelations  between  Fresh- 
water Mussels  and  Fishes — Life-histories  of  Parasites — Far- 
reaching  Influence  of  Certain  Animals:  Earthworms — Termites, 
or  White  Ants — The  Hand  of  Life  upon  the  Earth — Practical 
Importance  of  a  Realisation  of  the  Web  of  Life. 

NATURALISTS,  in  the  true  sense,  who  study  the 
life  of  living  creatures  in  nature,  have  always 
been  distinguished  by  a  keen  perception  of  the 
inter-relations  of  things.  Whether  we  take  Gilbert 
White  as  representing  the  old  school,  or  W.  H. 
Hudson  as  representing  the  new,  we  get  from 
their  observations  the  same  impression  of  nature 
as  a  vibrating  system,  most  surely  and  subtly  in- 
ter-connected. But  it  seems  just  to  say  that  no 
naturalist,  before  or  since,  has  come  near  Darwin 
in  his  realisation  of  the  web  of  life,  in  his  clear 
vision  and  picture  of  the  vast  system  of  linkages 
that  penetrates  throughout  the  animate  world. 

CORRELATION  OF  ORGANISMS  AS  WELL  AS  CORRE- 
LATION OF  ORGANS. — In  thinking  of  a  living  body 
we  are  accustomed  to  the  idea  of  the  correlation  of 

45 


46         DARWINISM   AND    HUMAN   LIFE 

organs.  It  is  of  the  very  nature  of  an  organism  that 
there  should  be  mutual  dependence  among  its  parts. 
The  organs  are  all  partners  in  the  business  of  life, 
and  if  one  member  changes  others  also  are  affected. 
This  is  especially  true  of  certain  organs  that  have 
developed  and  evolved  together,  and  are  knit  by 
close  physiological  bonds.  We  know  in  health 
how  nerve  and  muscle,  brain  and  sense-organs, 
heart  and  lungs,  are  closely  bound  together  in  the 
bundle  of  life.  We  know  in  disease  that  a  change 
in  one  organ  often  affects  another,  and  the  fact 
remains,  though  the  nexus  is  sometimes  mysterious. 
The  state  of  our  liver  may  give  colour  to  our  whole 
intellectual  firmament,  and  a  slight  ocular  de- 
rangement may  warp  a  wise  man's  philosophy. 
The  far-reaching  importance  of  a  little  organ  like 
the  thyroid  gland  beside  the  larynx  is  well  known ; 
our  intellectual  as  well  as  our  bodily  health  de- 
pends on  its  soundness.  Now,  just  as  there  is 
a  correlation  of  organs  within  the  body,  so  there 
is  a  correlation  of  organisms  in  that  system  of 
things  which  we  call  Nature.  In  both  cases  we 
are  here  using  the  word  "  correlation  "  in  its  deeper 
sense — that  the  various  parts  are  more  than 
mutually  dependent,  that  they  are  in  some  measure 
co-ordinated,  making  larger  systems  workable. 

WHAT  THE  METAPHOR  OP  "  THE  WEB  OF  LIFE  " 
SUGGESTS. — We  may  use  the  metaphor  "  web  of 
life  "  in  two  ways.  On  the  one  hand,  Nature  has  a 
woven  pattern  which  science  seeks  to  read,  each 
science  following  the  threads  of  a  particular  colour. 
There  is  a  warp  and  woof  in  this  web,  which  to  the 
zoologist  usually  appear  as  "  hunger  "  and  "  love/' 
There  is  a  changing  pattern  in  the  web,  becoming 
more  complex  as  the  ages  pass  ;  and  this  is  evo- 


THE    WEB    OF    LIFE  47 

lution.  But  the  essential  idea  of  a  web  is  that  of 
interlinking  and  ramifying.  We  can  never  tell 
where  a  thread  will  lead  to.  If  one  be  pulled  out, 
many  are  loosened.  This  is  true  of  Nature  through 
and  through. 

The  phrase  "  web  of  life "  suggests  another 
picture — the  web  of  a  spider — often  an  intricate 
system,  with  part  delicately  bound  to  part,  so  that 
the  whole  system  is  made  one.  "  The  quivering 
fly  entangled  in  a  corner  betrays  itself  throughout 
the  web ;  often  it  is  felt  rather  than  seen  by  the 
lurking  spinner.  So  in  the  substantial  fabric  of 
the  world  part  is  bound  to  part.  In  wind  and 
weather,  or  in  the  business  of  our  life,  we  are 
daily  made  aware  of  results  whose  first  conditions 
are  very  remote ;  and  chains  of  influence,  not 
difficult  to  demonstrate,  link  man  to  beast,  and 
flower  to  insect.  The  more  we  know  of  our 
surroundings  the  more  we  realise  that  nature  is 
a  vast  system  of  linkages,  that  isolation  is  im- 
possible." * 

DEPENDENCE  OF  LIVING  CREATURES  ON  THEIR 
SURROUNDINGS. — We  do  not  know  what  life  in 
principle  is,  but  we  may  describe  living  as  action 
and  reaction  between  organisms  and  their  en- 
vironment. This  is  the  fundamental  relation — 
the  dependence  of  living  creatures  on  appropriate 
surroundings,  and  the  primary  illustrations  of 
linkages  must  be  found  here.  The  living  creatures 
are  real,  just  in  the  same  sense  as  the  surroundings 
are  real ;  but  it  is  plain  that  we  cannot  abstract 
the  living  creatures  from  their  surroundings. 
When  we  try  to  do  this  they  die— even  in  our 
thought  of  them,  and  our  biology  is  only  necrology. 

1  "  The  Study  of  Animal  Life,"  by  J.  Arthur  Thomson  (1890). 


48         DARWINISM   AND    HUMAN   LIFE 

Huxley  compared  a  living  creature  to  a  whirlpool 
in  a  river ;  it  is  always  changing,  yet  always 
apparently  the  same  ;  matter  and  energy  stream 
in  and  stream  out ;  the  whirlpool  has  an  individu- 
ality and  a  certain  unity,  yet  it  is  wholly  dependent 
upon  the  surrounding  currents.  One  may  push 
the  whirlpool  metaphor  too  far,  so  as  to  give  a 
false  simplicity  to  the  facts,  for  when  vital  whirl- 
pools began  to  be  there  also  emerged  what  cannot 
be  discerned  in  crystal  or  dewdrop — the  will 
to  live,  a  capacity  of  persistent  experience,  and 
the  power  of  giving  rise  to  other  lives.  To  ignore 
this  is  to  attempt  a  falsely  simple  natural  history. 
But  what  Huxley's  metaphor  of  the  whirlpool 
does  vividly  express  is  the  dependence  of  living 
creatures  on  their  surroundings.  We  cannot  under- 
stand either  the  whirlpool  or  the  trout  apart  from 
the  stream. 

When  we  think  out  this  fundamental  dependence 
upon  surroundings,  we  see,  for  instance,  that  all 
our  supplies  of  energy,  all  our  powers  of  every 
kind — with  our  own  hands,  or  by  the  use  of  animals, 
or  by  means  of  machinery — are  traceable  to  the 
sun.  Or  again,  it  is  easy  to  show  that  our  society 
depends  fundamentally  not  on  gold,  but  on  iron. 
We  depend  for  food  on  plants  and  animals,  and 
through  these  animals  on  plants  ultimately ; 
the  plants  feed  upon  air,  water,  and  salts,  which, 
with  the  aid  of  the  energy  of  the  sunlight,  they 
build  up  into  complex  organic  compounds ;  they 
cannot  do  this  unless  the  sun  shines  through  a 
screen  of  green  pigment  called  chlorophyll ;  there 
cannot  be  chlorophyll  without  iron  ;  therefore  our 
whole  social  framework  is  founded  on  IRON. 

NUTRITIVE  CHAINS.— Plants  feed  on  their  in- 


THE    WEB    OP    LIFE  49 

animate  environment  in  a  direct  way  that  is 
impossible  to  animals,  so  we  pass  insensibly  from 
dependence  on  surroundings  to  those  nutritive 
chains  which  bind  living  creatures  together  in 
long  series  often  quaintly  suggestive  of  "  The 
House  that  Jack  Built "  and  similar  old  rhymes. 
We  have  ceased  to  wonder  at  the  circulation  of 
the  blood  in  our  body ;  have  we  begun  to  wonder 
enough  at  the  ceaseless  circulation  of  matter  in 
the  system  of  nature  ?  As  Heraclitus  said,  -rravra 
pel,  all  things  are  in  flux.  "  The  rain  falls ;  the 
springs  are  fed ;  the  streams  are  filled  and  flow 
to  the  sea ;  the  mist  rises  from  the  deep  and  the 
clouds  are  formed,  which  break  again  on  the 
mountain-side.  The  plant  captures  air,  water, 
and  salts,  and,  with  the  sun's  aid,  builds  them  up 
by  vital  alchemy  into  the  bread  of  life,  incorporating 
this  into  itself.  The  animal  eats  the  plant,  and  a 
new  incarnation  begins.  All  flesh  is  grass.  The 
animal  becomes  part  of  another  animal,  and  the 
reincarnation  continues." l  The  silver  cord  of  the 
bundle  of  life  is  loosed,  and  earth  returns  to  earth. 
The  microbes  of  decay  break  down  the  dead,  and 
there  is  a  return  to  air  and  water  and  salts.  We 
may  be  sure  that  nothing  real  is  ever  lost ;  we  are 
sure  that  all  things  flow.  Penelope-like,  Nature 
is  continually  unravelling  her  web  and  making  a 
fresh  start. 

NEXUS  BETWEEN  MUD  AND  CLEAR  THINKING. — 

To  keep  a  famous  inland  fish-pond  from  giving 
out,  some  boxes  of  mud  and  manure  were  placed 
at  the  sides.  Bacteria — the  minions  of  all  putre- 
faction— worked  in  the  mud  and  manure,  making 

1  "The    Bible   of    Nature,"    by    J.    Arthur  Thomson    (1908). 
(Scribner,  New  York.     Clark,  Edinburgh.) 

4 


50         DARWINISM   AND   HUMAN   LIFE 

food  for  minute  Infusorians,  which  multiply  so 
rapidly  that  there  may  be  a  million  from  one  in 
a  week's  time.,  A  cataract  of  Infusorians  over- 
flowed from  box  to  pond,  and  the  water-fleas  and 
other  small  fry  gathered  at  the  foot  of  the  fall 
and  multiplied  exceedingly.  Thus  the  fishes  were 
fed,  and,  as  fish-flesh  is  said  to  be  good  for  the 
brain,  we  can  trace  a  nexus  from  mud  to  clear 
thinking.  What  was  in  the  mud  became  part  of 
the  Infusorian,  which  became  part  of  the  Crus- 
tacean, which  became  part  of  the  fish,  which 
became  part  of  the  man.  And  it  is  thus  that 
the  world  goes  round. 

CORRELATION  BETWEEN  CATCHES  OF  MACKEREL 
AND  AMOUNT  OF  SPRING  SUNLIGHT.— A  curious  and 
most  interesting  correlation  has  been  discovered 
by  Dr.  E.  J.  Allen  between  catches  of  mackerel 
and  the  amount  of  sunlight.1  The  more  sunshine 
in  May,  the  more  mackerel  at  Billingsgate.  How 
does  this  work  out  ?  Mr.  G.  E.  Bullen 2  shows 
that  "  for  the  years  1903-1907  there  appears  to 
be  a  correlation  between  the  number  of  mackerel 
taken  during  May  and  the  amount  of  Copepod 
plankton,  upon  which  the  mackerel  feed,  taken 
in  the  neighbourhood  of  the  mackerel  fishing 
grounds  during  the  same  month."  Mr.  W.  J. 
Dakin  3  shows  that  the  food  of  Copepods  consists 
largely  of  the  vegetable  organisms  of  the  plankton, 
such  as  diatoms,  and  of  Infusorian-]  ike  organisms 
called  Peridinidae.  But  the  production  of  this 
microscopic  plankton,  the  "  stock  "  of  the  "sea- 
soup,"  depends  partly  on  the  composition  of  the 

1  Journ.  Marine  Biol.  Assoc.  (1909),  vol.  viii.  p.  394. 

*  Ibid.  p.  269. 

»  Internal.  Revue  Hydrobiologie  (1908),  voL  L 


THE    WEB    OF   LIFE  51 

sea-water,  partly  on  the  temperature,  and  partly 
on  the  amount  of  light  available.  There  seems  to 
be  no  correlation  between  the  surface  temperature 
and  the  abundance  of  mackerel,  but  Dr.  Allen  has 
shown  a  correspondence  between  sunshine  and 
the  catches.  Thus  we  see  that,  if  all  flesh  is  grass, 
then  in  the  same  sense  all  fish  is  diatom. 

NUTRITIVE  CHAINS  IN  THE  DEEP  SEA. — If  we 
pass  from  the  sunlit  open  sea  to  the  floor  of  the 
deep  sea — that  strange,  dark,  cold,  silent,  plantless 
world — we  find  carnivorous  animal  preying  upon 
carnivorous  animal  through  long  series — fish  feeds 
on  fish,  fish  on  crustacean,  crustacean  on  worm, 
worm  on  still  smaller  fry,  and  all  ultimately  depend 
on  the  basal  food-supply — the  ceaseless  shower  of 
moribund  atomies  sinking  from  the  surface  waters 
many  miles,  it  may  be,  overhead,  like  the  snow- 
flakes  on  a  quiet  winter  day. 

DEPENDENCE  OF  ONE  ORGANISM  ON  ANOTHER 
FOR  THE  CONTINUANCE  OF  THE  SPECIES. — Passing 
from  "  nutritive  chains,"  we  may  select  a  few 
illustrations  of  the  dependence  of  one  creature 
upon  another  for  the  continuance  of  its  kind. 
The  crowning  instances  are  to  be  found  in  the 
interrelations  between  plants  and  animals  which 
secure  cross-fertilisation  and  the  distribution  of 
seeds.  To  both  of  these  Darwin  devoted  much 
attention,  and  they  were  always  favourite  subjects 
with  him. 

Every  one  knows  that  flowering  plants  and 
flower-visiting  insects  have  grown  up  throughout 
long  ages  together,  in  alternate  influence  and 
mutual  perfecting.  They  are  now  fitted  to  one 
another  as  hand  to  glove.  The  insects  visit  the 
flowers  for  food  ;  in  so  doing  they  carry  the  fer- 


52         DARWINISM   AND    HUMAN    LIFE 

tilising  golden  dust  from  blossom  to  blossom,  so 
that  the  possible  seeds  become  real  seeds. 

In  1793  a  Berlin  naturalist,  Christian  Konrad 
Sprengel,  like  Darwin  in  his  perception  of  the 
web  of  life,  published  a  pioneer  book  entitled 
"  The  Secret  of  Nature  discovered  in  the  Structure 
and  Fertilisation  of  Flowers,"  in  which  he  showed 
that  most  flowers  have  nectar  which  insects 
enjoy;  that  by  the  insects'  visits  pollination  is 
secured ;  that  there  is  no  detail  of  the  flower  without 
its  meaning — the  colour  is  a  flag  to  attract  the 
insect's  eye,  conspicuous  spots  are  honey-guides 
to  the  explorers,  there  are  arrangements  for  keeping 
the  pollen  dry  and  for  dusting  it  on  the  insects, 
and  so  on.  If  Sprengel  had  only  discovered  the 
utility  of  the  cross-fertilisation,  which  Darwin 
proved  experimentally,  his  work  could  hardly 
have  been  overlooked  for  nearly  seventy  years. 
In  1841  it  came  into  Darwin's  hands,  and  im- 
pressed him  as  being  "  full  of  truth,"  although 
"  with  some  little  nonsense."  In  Darwin's  work 
Sprengel  had  his  long-delayed  reward. 

DARWIN'S  INSTANCE  OF  THE  CONNECTION  BE- 
TWEEN CATS  AND  CLOVER. — One  of  Darwin's 
instances  of  the  web  of  life — given  in  connection 
with  the  pollination  of  flowers — has  become 
familiar  all  over  the  world.  It  should  never 
become  trite  to  us  and  it  should  never  be  regarded 
as  more  than  a  particularly  clear  illustration  of 
a  general  fact.  "  Plants  and  animals,  remote  in 
the  scale  of  nature,  are  bound  together  by  a  web 
of  complex  relations.  ...  I  have  found,  from 
experiments,  that  humble-bees  are  almost  indis- 
pensable to  the  fertilisation  of  the  heart 's-ease 
(Viola  tricolor),  for  other  bees  do  not  visit  this 


THE   WEB    OF   LIFE  53 

flower.  I  have  also  found  that  the  visits  of  bees 
are  necessary  for  the  fertilisation  of  some  kinds 
of  clover — thus,  100  heads  of  red  clover  (Tri- 
folium  pratense)  produced  27,000  seeds,  but  the 
same  number  of  protected  heads  produced  not  a 
single  seed.  Humble-bees  alone  visit  red  clover, 
as  other  bees  cannot  reach  the  nectar.  .  .  .  Hence 
we  may  infer  as  highly  probable  that,  if  the  whole 
genus  of  humble-bees  became  extinct  or  very 
rare  in  England,  the  heart's-ease  and  red  clover 
would  become  very  rare,  or  wholly  disappear." 
We  know  that  the  red  clover  imported  to  New 
Zealand  did  not  bear  fertile  seeds  until  humble- 
bees  were  also  imported.  "  The  number  of  humble- 
bees  in  any  district  depends  in  a  great  measure 
on  the  number  of  field-mice,  which  destroy  their 
combs  and  nests ;  and  Colonel  Newman,  who  has 
long  attended  to  the  habits  of  humble-bees, 
believes  that  more  than  two-thirds  of  them  are 
thus  destroyed  all  over  England."  Now  the 
number  of  mice  is  largely  dependent,  as  every 
one  knows,  on  the  number  of  cats ;  and  Colonel 
Newman  says :  "  Near  villages  and  small  towns 
I  have  found  the  nests  of  humble-bees  more  numer- 
ous than  elsewhere,  which  I  attribute  to  the 
number  of  cats  that  destroy  the  mice."  Thus  we 
may  say,  with  Darwin,  that  next  year's  crop  of 
purple  clover  is  influenced  by  the  number  of 
humble-bees  in  the  district,  which  varies  with 
the  number  of  field-mice ;  that  is  to  say,  with  the 
abundance  of  cats  ! 

SCATTERING  OF  SEEDS. — It  is  a  fascinating 
chapter  of  natural  history  which  tells  us  how 
cross-pollination  is  effected — here  by  a  bee  and 
there  by  a  butterfly,  occasionally  by  a  long-billed 


64         DARWINISM   AND    HUMAN    LIFE 

humming-bird  beautifully  poised  before  the  flower 
with  almost  invisibly  rapid  vibrations  of  its  wings, 
and  occasionally  by  a  slowly  moving  snail  of 
epicure  appetite.  But  not  less  important  is  the 
part  played  by  animals  in  the  scattering  of  seeds, 
and  here  again  Darwin  gives  us  the  classic  case 
of  fourscore  seeds  germinating  out  of  a  ball  of 
mud  from  a  bird's  foot.  From  one  instance  you 
may  learn  all,  and  see  that  much  of  Darwin's 
work  has  been  an  eloquent  commentary  on  that 
memorable  saying  about  the  sparrow  that  falls 
to  the  ground.  Such  a  simple  event  literally 
sends  a  throb  through  surrounding  nature ;  we 
can  follow  its  effects  a  few  steps,  just  as  we  follow 
for  a  few  yards  the  ripples  made  when  we  throw 
a  stone  into  a  still  lake :  in  neither  case  can  we 
doubt  that  the  spreading  influences  are  real, 
though  they  pass  beyond  our  ken. 

INTERRELATIONS  BETWEEN  FRESH-WATER  MUS- 
SELS AND  FISHES. — As  a  striking  illustration  of 
the  inter-linking  of  different  forms  of  life,  we 
may  take  the  case  of  the  fresh- water  mussels  and 
their  larvae.  The  fertilised  eggs  develop  in  the 
outer  gill-plate  of  the  mother-mussel,  and  minute 
bivalve  larvae,  called  Glochidia,  are  formed.  The 
mussel  keeps  these  within  the  cradle  until  a  fresh- 
water fish — such  as  the  minnow — comes  into  the 
vicinity,  and  then  she  sets  them  free.  In  a  way 
that  we  do  not  understand,  the  simple  constitution 
of  the  larvae  is  tuned  to  respond  to  the  presence  of 
minnows  and  the  like,  and  with  snapping  valves 
they  manage  to  fix  themselves  to  their  host. 
After  a  short  period  of  temporary  parasitism,  at 
the  end  of  which  there  is  a  metamorphosis,  they 
drop  off  from  the  fish  into  the  mud,  often  far 


THE    WEB    OF    LIFE  55 

from  their  birth-place.  This  is  curious  enough, 
but  the  idea  of  linkages  becomes  incandescent  in 
the  mind  when  we  note  that,  just  as  the  fresh- water 
mussel  has  young  temporarily  parasitic  on  fishes,  so 
a  fresh-water  fish,  the  bitterling  (Rhodeus  amarus), 
has  its  young  temporarily  parasitic  in  the  gills 
of  the  mussel. 

LIFE-HISTORIES  OF  PARASITES. — When  we  pass 
to  parasites  in  a  stricter  sense  we  find  the  most 
extraordinary  interconnections,  the  most  widely 
separated  animals  often  sharing  a  parasite  between 
them.  Liver-rot,  which  has  repeatedly  killed  a 
million  sheep  in  a  year  in  Britain  alone,  is  due 
to  a  parasite  which  passes  from  sheep  to  water, 
from  water  to  water-snail,  from  water-snail  to 
grass,  from  grass  to  sheep.  The  tapeworm  of  the 
cat  has  its  bladder-worm  stage  in  the  mouse,  the 
sturdie-worm  of  the  sheep's  brain  has  its  tapeworm 
stage  in  the  dog,  and  similar  relations  hold  for 
hundreds  of  species.  The  troublesome  thread- 
worm of  human  blood  (Filaria  sanguinis  hominis) 
is  transferred  from  man  to  man  by  the  mosquito, 
and  the  guinea-worm,  which  was  probably  the 
fiery  serpent  that  vexed  the  Israelites  in  the 
desert,  which  passes  into  man  in  drinking-water, 
spends  its  youth  in  a  minute  water-flea,  called 
by  the  giant's  name  of  Cyclops.  The  import- 
ance of  tse-tse  flies  in  transmitting  the  minute 
animals  which  cause  sleeping-sickness  and  allied 
diseases  is  known  to  all.  We  have  spoken  of  the 
connection  between  cats  and  clover,  and  there 
is  a  not  less  striking  connection  between  cats 
and  plague.  For  it  seems  to  have  been  shown 
in  India  that  the  more  cats  the  fewer  rats, 
and  the  fewer  rats  the  fewer  rat-fleas,  which 


56         DARWINISM    AND    HUMAN    LIFE 

are  the  agents  in  passing   the   plague-germs   to 
man. 

FAR-REACHING  INFLUENCE  OF  CERTAIN  ANIMALS  : 
EARTHWORMS. — We  realise  the  idea  of  the  web 
of  life  in  another  way  when  we  consider  the 
far-reaching  influence  of  particular  kinds  of  acti- 
vity, the  best  instance  being  the  work  of  earth- 
worms. In  1777  Gilbert  White  got  at  the  very 
root  of  the  matter.  "  The  most  insignificant 
insects  and  reptiles  are  of  much  more  consequence 
and  have  much  more  influence  in  the  economy 
of  nature  than  the  incurious  are  aware  of.  ... 
Earthworms,  though  in  appearance  a  small  and 
despicable  link  in  the  chain  of  nature,  yet,  if 
lost,  would  make  a  lamentable  chasm.  .  .  . 
Worms  seem  to  be  the  great  promoters  of  vege- 
tation, which  would  proceed  but  lamely  without 
them,  by  boring,  perforating,  and  loosening  the 
soil,  and  rendering  it  pervious  to  rains  and  the 
fibres  of  plants ;  by  drawing  straws  and  stalks 
of  leaves  and  twigs  into  it ;  and,  most  of  all, 
by  throwing  up  such  infinite  numbers  of  lumps 
of  earth  called  worm-casts,  which,  being  their 
excrement,  is  a  fine  manure  for  grain  and  grass. 
Worms  probably  provide  new  soil  for  hills  and 
slopes  where  the  rain  washes  the  earth  away ;  and 
they  affect  slopes  probably  to  avoid  being  flooded. 
.  .  .  The  earth  without  worms  would  soon  become 
cold,  hard-bound,  and  void  of  fermentation,  and 
consequently  sterile.  .  .  .  These  hints  we  think 
proper  to  throw  out,  in  order  to  set  the  inquisitive 
and  discerning  at  work.  A  good  monograph  of 
worms  would  afford  much  entertainment  and 
information  at  the  same  time,  and  would  open  a 
large  and  new  field  in  natural  history." 


THE    WEB    OF   LIFE  57 

The  monograph  that  Gilbert  White  wished  for 
in  1777  was  published  by  Darwin  in  1881,  the 
year  before  he  died — "  the  completion,"  he  said, 
"  of  a   short  paper  read   before   the   Geological 
Society  more  than  forty  years  ago."    With  his 
characteristic  thoroughness  and  patience  he  worked 
out  the  part  that  earthworms  have  played  in  the 
history  of  the  earth,  and  proved  that  they  deserve 
to  be  called  the  most  useful  animals.     By  their 
burrowing  they   loosen   the   earth,   making  way 
for  the   plant  rootlets   and   the   raindrops ;     by 
bruising  the  soil  in  their  gizzards,  they  reduce 
the  particles  to  more  useful,  powdery  form ;    by 
burying  the  surface  with  castings  brought  up  from 
beneath,  they  have  been  for  untold  ages  ploughers 
before  the  plough,  and  by  burying  leaves  they 
have  made  a  great  part  of  the  vegetable  mould 
over  the  whole  earth.     In  illustration  of  the  last 
point,  we  may  notice  that  we  recently  found  thir- 
teen midribs  of  the  leavesof  the  rowan,  or  mountain- 
ash,   radiating  round  one   hole   like   the   spokes 
of  a  wheel ;  the  withering  leaflets  had  been  carried 
down,  and  two  were  sticking  up  at  the  mouth  of 
the  burrow :    that  meant  91  leaflets  to  one  hole. 
Darwin  showed  that  there  often  are  50,000  (and 
there  may  be  500,000)  earthworms   in  an  acre ; 
that  they  often  pass  ten  tons  of  soil  per  acre 
per  annum  through  their  bodies;    and  that  they 
often  cover  the  surface  at  the  rate  of  three  inches 
in  fifteen  years.     Though  our  British  worms  only 
pass  out  about  20  oz.  of  earth  in  a  year,  the  weights 
thrown  up  in  a  year  on  two  separate  square  yards 
which  Darwin  watched  were  respectively  6*75  Ib. 
and  8-387  Ib.,  which  correspond  to  14J  and  18 
ton£  per  acre  per  annum. 


58        DARWINISM   AND   HUMAN    LIFE 

We  follow  the  work  further  and  it  becomes 
evident  that  the  constant  exposure  of  the  soil 
bacteria  on  the  surface  is  bound  to  be  important, 
on  the  one  hand,  in  allowing  them  to  be  scattered 
by  wind  and  rain,  on  the  other  in  exposing 
them  to  the  beneficent  action  of  the  sunlight — 
which  is  the  most  universal,  effective,  and  eco- 
nomical of  all  germicides. 

In  Yorubaland,  on  the  West  Coast  of  Africa, 
Mr.  Alvan  Millson  calculated  that  about  62,233 
tons  of  subsoil  are  brought  every  year  to  the  sur- 
face of  each  square  mile,  and  that  every  particle 
of  earth,  to  the  depth  of  two  feet,  is  brought  to 
the  surface  once  in  twenty-seven  years.  It  need 
hardly  be  added  that  the  district  is  fertile  and 
healthy. 

Earthworms  play  their  part  in  the  disintegration 
of  rocks,  letting  the  solvent  humus-acids  of  the 
soil  down  to  the  buried  surface.  Their  castings 
on  the  hill-slopes  are  carried  down  by  wind  and 
rain  and  go  to  swell  the  alluvium  of  the  distant 
valleys  or  the  wasted  treasures  of  the  sea.  The 
well-known  parallel  ledges  along  the  slopes  of 
grass-clad  hills  are  partly  due  to  earthworm 
castings  caught  on  sheep-tracks,  and  thus  we 
begin  to  connect  the  earthworms  not  only  with 
our  wheat-supply  but  with  our  scenery.  Well 
may  we  say,  with  Darwin  :  "  It  may  be  doubted 
whether  there  are  many  other  animals  which  have 
played  so  important  a  part  in  the  history  of  the 
world  as  have  these  lowly  organised  creatures." 
Those  who  wish  to  understand  Darwinism  should 
always  begin  with  Darwin's  last  book — "  The 
Formation  of  Vegetable  Mould  through  the  Action 
of  Worms  "  (1881).  It  illustrates  the  web  of  life, 


THE    WEB    OF    LIFE  59 

the  idea  of  which  is  essential  to  an  understanding 
of  the  struggle  for  existence  and  natural  selection. 
But  it  also  illustrates  what  Darwin  had  learned 
from  Lyell — that  great  results  may  be  brought 
about  by  the  accumulation  of  infinitesimal  items. 
As  Prof.  A.  Mimes  Marshall  said :  "  The  lesson 
to  be  derived  from  Darwin's  life  and  work  cannot 
be  better  expressed  than  as  the  cumulative  import- 
ance of  infinitely  little  things." 

TERMITES,  OR  WHITE  ANTS. — Henry  Drummond, 
in  his  "  Tropical  Africa,"  tried  to  make  out  a  case 
for  the  agricultural  importance  of  termites,  or 
white  ants.  It  is  well  known  that  these  old- 
fashioned  insects  have  a  pruning  action  in  the 
forest,  destroying  dead  wood  with  great  rapidity. 
Houses  and  furniture,  fences  and  boxes,  as  well 
as  forest-trees,  fall  under  their  jaws.  In  some 
places,  "  if  a  man  lay  down  to  sleep  with  a  wooden 
leg,  it  would  be  a  heap  of  sawdust  in  the  morning." 
But  what  of  the  termites'  agricultural  importance  ? 
The  point  is  that  they  keep  the  soil  circulating 
by  constructing  earthen  tunnels  up  the  sides  of 
trees  and  posts  and  by  making  huge  obelisk-like 
ant-hills,  or  termitaries.  "  The  earth-tubes  crumble 
to  dust,  which  is  scattered  by  the  wind  ;  the  rains 
lash  the  forests  and  soils  with  fury,  and  wash  off 
the  loosened  grains  to  swell  the  alluvium  of  a 
distant  valley."  It  must  be  noted,  however, 
that  Drummond  did  not  prove  his  case  with  suffi- 
cient precision,  and  there  is,  as  Escherich  points 
out  in  his  beautiful  study  of  termites,1  this  difficulty, 
that,  while  the  castings  of  earthworms  are  soft 
and  loose,  the  earth-tubes  and  constructions  of 
termites  are  stony. 

1  "  Die  Termiten."    (Leipzig,  1909.) 


60         DARWINISM    AND    HUMAN    LIFE 

Escherich  does,  however,  admit  that  the  termites 
have  some  agricultural  importance,  and  he  points 
out  that  there  are  other  services  to  be  put  to 
the  credit  side  of  their  account.  They  prune  off 
wood  that  has  begun  to  go  ;  they  destroy  rotting 
things,  including  the  bodies  of  small  animals ; 
they  make  for  cleanliness  and  health.  In  some 
low-lying  tracts,  as  Silvestri  has  shown,  there  are 
dry  stretches,  "  termite  islands,"  which  have 
been  gradually  built  up  from  the  broken-down 
remains  of  termitaries.  Nor  should  it  be  forgotten 
that  the  white  ants  are  often  used  as  food.  On 
the  other  hand,  Escherich  does  not  hesitate  to 
rank  them  as  among  the  great  hindrances  to 
the  spread  of  civilisation.  They  insidiously  devour 
everything  wooden,  from  the  telegraph-post  to 
the  wooden  butt  of  the  gun  hanging  against  the 
wall,  from  books  in  the  library  to  corks  in  the 
cellar.  There  does  not  seem  sufficiently  precise 
information  in  regard  to  the  living  plants  that 
they  attack,  and  no  safe  general  statement  can  be 
made  except  that  their  appetite  is  large  and 
catholic. 

With  a  centre  in  earthworms,  what  a  variety  of 
interests  must  be  included  within  the  radius  of 
their  life  and  work! — centipedes,  birds,  moles, 
seedlings,  man.  The  same  is  true  of  termites, 
and  two  further  illustrations  may  be  given.  Ob- 
servers have  reported  about  thirty  different  species 
of  termites  with  the  habit  of  feeding  on  fungi 
grown  within  the  termitary  on  specially  constructed 
mazy  beds.  The  habit  is  interesting  in  many  ways ; 
for  instance,  because  the  fungi  afford  a  supply  of 
nitrogenous  material  which  is  scarce  in  the  ordinary 
diet  of  wood,  and  also  because  a  similar  habit 


THE    WEB    OF    LIFE  61 

occurs  in  the  quite  unrelated  true  ants.  Finally, 
the  web  is  illustrated  by  the  numerous  boarders, 
mostly  beetles,  that  are  found  in  the  termitaries — 
not  hostile  intruders  or  parasites,  but  guests  which 
are  fed  and  cared  for  apparently  for  the  sake  of 
a  palatable  exudation  with  a  pleasant,  narcotising 
effect  on  the  termites.  With  a  centre  in  termites, 
what  a  variety  of  interests  must  we  not  include 
within  the  radius  of  their  life  and  work ! — fungi 
and  trees,  beetles  and  birds,  lizards  and  ant-eaters, 
and  man  more  than  any. 

THE  HAND  OF  LIFE  UPON  THE  EARTH. — The 
hand  of  life  has  been  working  upon  the  earth  for 
untold  ages.  Take  plants,  for  instance.  The  sea- 
weeds lessen  the  force  of  the  waves,  the  lichens 
eat  into  the  rocks,  the  mosses  form  huge  sponges 
on  the  moors  which  keep  the  streams  flowing 
in  days  of  drought.  Many  little  plants  are  for 
ever  smoothing  away  the  wrinkles  on  the  earth's — 
their  mother's — face,  and  they  adorn  her  with 
jewels.  Others  that  have  formed  coal  have  en- 
riched her  with  ages  of  entrapped  sunlight.  The 
grass — which  began  to  appear  in  Tertiary  ages — 
protects  the  earth  like  a  garment ;  the  forests 
affect  rainfall  and  temper  climate,  besides  sheltering 
multitudes  of  living  things,  to  many  of  whom  every 
blow  of  the  axe  is  a  death-knell.  No  plant,  from 
bacterium  to  oak-tree,  lives  or  dies  to  itself,  or 
is  without  its  influence  upon  the  earth.  So  among 
animals  there  are  destructive  borers  and  burrowers 
and  conservative  agents,  such  as  the  coral-polyps 
and  the  chalk-forming  Foraminifera. 

PRACTICAL  IMPORTANCE  OF  A  REALISATION  OF 
THE  WEB  OF  LIFE. — What  has  Darwinism  to  do 
with  human  life  ?  The  answer  at  this  stage  in 


62         DARWINISM   AND    HUMAN   LIFE 

our  inquiry  is  clear :  we  must  respect  the  web 
of  life  if  we  wish  to  master  Nature.  She  must 
be  humoured,  not  bullied.  Emerson  included  in 
his  vision  of  a  perfected  earth  the  absence  of 
spiders,  but  the  absence  of  spiders — which  snare 
so  many  injurious  insects — would  mean  the  absence 
of  much  else,  man  probably  included.  In  a 
northern  county  in  Scotland  the  proprietors  were 
justly  annoyed  at  the  injuries  inflicted  on  young 
trees  by  squirrels,  and  they  formed  a  squirrel- 
club,  setting  a  price  on  the  beautiful  rodent's 
head.  Perhaps  a  wiser  course  would  have  been  to 
begin  by  inquiring  what  disturbance  of  the  balance 
of  nature  had  allowed  the  squirrels  to  multiply 
so  disastrously.  But,  after  a  period  of  squirrel- 
slaughter  and  some  jubilation  thereat,  a  cloud 
began  to  rise  in  the  sky.  The  wood-pigeons  were 
multiplying  worse  than  ever,  and  the  farmers, 
at  least,  said  with  no  uncertain  voice  that  they 
preferred  the  squirrels.  An  imperfect  recognition 
of  the  web  of  life  had  left  out  of  account  the 
notable  fact  that  squirrels  destroy  large  numbers 
of  young  wood-pigeons. 

One  of  the  hopeful  symptoms  of  the  last  few 
years  is  the  reawakening  of  an  interest  in  woods 
and  forests.  Every  one  knows  how  terribly  these 
have  been  wasted,  and  how  the  disastrous  results 
have  affected  rainfall  and  irrigation,  climate  and 
crops,  and  even  the  character  of  the  people.  Here 
what  was  once  a  pleasant  stream  is  now  like  a 
gravelly  road,  and  there  the  fertile  plains  are 
flooded ;  here  the  wind  is  sweeping  away  the 
soil,  and  there  both  beauty  and  health  have 
departed.  The  birds  which  the  woods  once 
sheltered  are  driven  elsewhere,  and  the  insect- 


THE    WEB    OF    LIFE  63 

pests  are  rife  among  the  crops.  For  "  the  cheapest 
and  most  effective  insecticides  are  birds." 

The  recognition  of  consequences — often  far- 
reaching — grows  with  us  as  we  work  with  the 
idea  of  the  web  of  life,  as  we  see  in  proper 
perspective  the  criminality  of  those  who  are 
ruthless.  President  Roosevelt1  has  declared  his 
abomination  of  "  the  land-skinner  " — "  the  in- 
dividual whose  idea  of  developing  the  country  is 
to  cut  every  stick  of  timber  of  it,  and  then  leave 
a  barren  desert  for  the  home-maker  who  comes 
in  after  him.  That  man  is  a  curse,  and  not  a 
blessing,  to  the  country.  The  prop  of  the  country 
must  be  the  man  who  intends  so  to  run  his  business 
that  it  will  be  profitable  to  his  children  after  him." 
Every  right-thinking  man,  and  especially  those 
who  have  grasped  the  idea  of  the  web  of  life, 
will  say  with  Roosevelt,  "  /  am  against  the  land- 
skinner  every  time." 

It  may  be  said  that  man  must  exterminate  a 
good  deal  if  he  is  to  go  on  peaceably  with  his 
business,  and  it  will  be  admitted  that  there  has 
never  been  a  strong  enthusiasm,  humanitarian  or 
otherwise,  against  the  elimination  of  rattlesnakes, 
and  such  like.  The  naturalist's  answer  is  that 
every  crusade  should  be  carefully  considered  on 
its  own  merits,  and  that  every  careless  and  hasty 
destruction  of  life  is  to  be  condemned.  Even  in 
regard  to  snakes  killing  may  be  carried  too  far. 
Some  creatures  are,  as  it  were,  on  the  fringes  of  the 
web,  while  others  occupy  a  position  where  many 
threads  meet.  It  is  scientifically  and  aesthetically 
deplorable  that  birds  like  the  great  auk  and 

1  Quoted  by  A.  H.  8.  Lucas  in  his  admirable  Presidential  Address, 
"Proc.  Linnean  Soc.  N.S.W."  (1908),  vol.  xxxiii.  pp.  1-38. 


64         DARWINISM   AND    HUMAN   LIFE 

mammals  like  the  quagga  should  have  been  exter- 
minated, but  it  is  practically  much  more  deplorable 
that  we  have  lost  so  many  hawks  and  weasels 
and  other  members  of  that  pertinacious  army 
whose  guerilla  warfare  keeps  hundreds  of  more 
humdrum  creatures  up  to  the  scratch,  and  keeps 
"  vermin "  from  becoming  a  plague.  Moreover, 
it  is  extremely  difficult  to  tell  what  may  be  the 
consequences  of  exterminating  any  creature — 
remote  as  it  may  seem  from  the  beaten  track  of 
human  affairs.  One  of  the  obvious  lessons  of 
Darwinism  is  that  we  should  be  slow  to  call  any 
change  unimportant.  Everything  counts,  or  may 
count.  A  so-called  unimportant  animal  is  destroyed 
and  no  immediate  ill  effects  are  seen.  But  who 
can  tell  ? 

Very  pertinent,  for  instance,  is  the  question : 
What  about  the  parasites  that  used  to  complete 
their  life-history  in  romantic  routine  in  this  ex- 
tinguished animal  ?  Have  we  extinguished  the 
parasite  also  ?  Or  is  it  waiting,  with  a  whip  of 
scorpions,  to  chastise  mankind  for  their  ignorance 
of  Darwinism  ? 

The  practical  importance  of  recognising  the 
web  of  life  has  been  proved  by  the  heavy  penalties 
which  man  has  often  had  to  pay  for  disturbing 
the  balance  of  nature,  careless  of  results  and 
ruthless  of  beauty,  for  not  admitting  that  if  we 
would  master  Nature  we  must  first  understand 
her.  How  much  has  Australia  had  to  pay  for 
the  introduction  of  rabbits  in  1860,  or  America 
for  sparrows  ?  Sometimes  the  introduction  has 
been  unconscious,  and  man  has  only  to  blame 
himself  for  letting  the  intruder  take  hold,  as  in 
the  case  of  the  Phylloxera  in  France,  or  of  the 


THE    WEB    OF    LIFE  65 

Colorado  Beetle  in  Ireland.  "  Ignorance  of  nature," 
Mr.  A.  H.  S.  Lucas  says,  "  is  costly.  By  disturbing 
the  balance  of  nature,  man  has  introduced  foes 
into  his  own  household."  Speaking  of  Australia, 
he  says  :  "  How  much  is  needed  for  the  eradication 
of  Bathurst  Burr,  Prickly  Pear,  Water-hyacinth, 
Bramble  and  Sweetbriar,  Codlin  Moth,  Waxy 
Scale,  Pear  Slug,  and  Red  Spider,  owing  to  care- 
lessness or  lack  of  knowledge  in  early  days  ?  " l 

An  obvious  moral  is  that  we  should  be  careful 
in  our  introductions  of  new  organisms — man 
included — into  new  surroundings.  The  primary 
consequences  may  be  predictable,  but  the  secondary 
and  the  tertiary  consequences — who  is  sufficient 
for  these  things  ?  We  have  records  of  the  un- 
conscious introduction  of  rats  into  Jamaica,  where 
they  became  a  pest.  To  destroy  them  mongooses 
were  imported,  and  the  rats  were  soon  checked. 
But  the  mongooses,  having  finished  the  rats,  began 
to  eat  up  the  poultry  and  young  birds  of  various 
kinds.  As  this  went  on  the  injurious  insects  and 
ticks,  that  the  birds  used  to  eat,  began  to  gain 
the  ascendant.  A  recent  report — which  requires 
confirmation — says  that  the  increase  of  ticks  is 
making  life  a  burden  to  the  mongooses.  Thus  a 
balance  will  be  again  arrived  at.  There  is  no 
doubt  of  that,  but  how  much  is  often  unnecessarily 
lost  by  the  way ! 

1  "  Presidential  Address,  Proc.  Linnean  Society  N.S.  Wales  " 
(1908),  voL  xxxiii.  pp.  1-38. 


CHAPTER  III 
THE  STRUGGLE  FOR  EXISTENCE 


67 


CHAPTER   III 

THE   STRUGGLE   FOR  EXISTENCE 

The  Idea  not  so  Simple  as  it  seems — The  Anthropomorphism  of 
the  Idea — Different  Forms  of  the  Struggle  for  Existence — 
Struggle  for  Existence  in  the  Plant  World — Illustration  of  the 
Complexity  of  the  Struggle  for  Existence — Reasons  for  the 
Struggle  for  Existence — Results  of  the  Struggle  for  Existence — 
Breadth  of  the  Darwinian  Concept  of  the  Struggle  for 
Existence — The  other  Side  of  the  Struggle  for  Existence — 
Mutual  Aid — Application  of  the  Concept  to  Human  Life. 

THE  IDEA  NOT  so  SIMPLE  AS  IT  SEEMS. — No  evolu- 
tionist phrase  is  more  familiar  than  "  the  struggle 
for  existence/'  which  has  passed  into  everyday 
usage.  Yet  it  is  not  easy  to  grasp  its  full  meaning, 
or  to  keep  it  vividly  in  mind.  "  Nothing  is  easier," 
Darwin  said,  "  than  to  admit  in  words  the  truth 
of  the  universal  struggle  for  life,  or  more  difficult — 
at  least  I  have  found  it  so — than  constantly  to 
bear  this  conclusion  in  mind.  Yet,  unless  it  be 
thoroughly  engrained  in  the  mind,  the  whole 
economy  of  nature,  with  every  fact  on  distribution, 
rarity,  abundance,  extinction,  and  variation,  will 
be  dimly  seen  or  quite  misunderstood."1 

If  a  recognition  of  the  "  struggle  for  existence  " 
is  essential  to  a  clear  outlook  on  nature,  and 
if  Darwin  found  difficulty  in  bearing  it  constantly 
in  mind,  we  must  be  prepared  to  take  some  pains 
in  trying  to  get  a  grasp  of  the  facts  which  the 

i  "  The  Origin  of  Species,"  p.  49. 


70         DARWINISM   AND    HUMAN   LIFE 

phrase  sums  up.  This  is  the  more  desirable  since 
there  is  often  tyranny  in  a  phrase,  especially  when 
it  is  misunderstood.  Are  we  sure  that  we  under- 
stand what  the  struggle  for  existence  means  ? 
Are  we  clear  that  it  means  much  more  than  the 
bare  words  suggest  ?  Do  we  understand  that 
the  phrase  is  a  biological  formula  which  has  at 
the  same  time  the  misfortune  of  being  an  anthro- 
pomorphic metaphor  ? 

From  ancient  days  there  had  been  a  recognition 
of  a  struggle  in  nature — we  find  the  idea  expressed 
by  Aristotle  and  by  Lucretius,  and  more  definitely 
by  several  of  the  pioneers  of  modern  evolution 
theory — but  it  was  Darwin  who  first  realised  its 
length  and  breadth,  its  height  and  depth,  and, 
what  is  more,  its  dynamic  significance.1 

THE  ANTHROPOMORPHISM  OF  THE  IDEA. — In 
trying  to  understand  the  past  and  present  of 
living  creatures  naturalists  have  followed  with 
some  success  two  very  different  methods,  which 
seem  opposed  to  one  another,  but  are  rather 
complementary.  The  one  method  is  to  inquire 
into  the  material  machinery  of  vital  activity,  to 
throw  on  the  puzzling  drama  of  life  the  light  of 
chemistry  and  physics.  This  is  a  sound  method 
as  far  as  it  goes.  The  celery  is  blanched  because 

1  It  is  interesting  to  notice  how  often  Tennyson  turns  to  certain 
aspects  of  the  struggle  for  existence,  as  when  he  speaks  of  Nature 
"  red  in  tooth  and  claw  with  ravine,"  "  So  careless  of  the  single 
life,"  or  in  the  well-known  lines : 

"  For  life  is  not  as  idle  ore  ; 

But  iron  dug  from  central  gloom, 
And  heated  hot  with  burning  fears, 
And  dip't  in  baths  of  hissing  tears, 

And  batter'd  by  the  shocks  of  doom 

To  shape  and  use." 


THE   STRUGGLE    FOR   EXISTENCE        71 

it  is  hidden  from  the  light ;  the  child  is  pale 
because,  roughly  speaking,  it  has  not  enough  of 
iron  in  its  blood.  The  defect  of  the  method  is 
that,  unless  its  partiality  be  borne  in  mind,  it 
is  apt  to  give  a  false  simplicity  to  the  facts,  for 
it  is  quite  certain  that  we  cannot  at  present  re- 
describe  vital  happenings  in  terms  of  modern 
physics  and  chemistry — vitalistic  as  these  are. 
The  old  materialism  has  been  found  out. 

The  other  method  is  to  read  man  into  the 
beasts  and  even  into  the  flowers  of  the  field,  to 
interpret  the  life  of  animals  and  plants  in  terms 
of  human  life.  This  is  also  a  sound  method  as 
far  as  it  goes.  Its  defect  is  that,  verification 
being  difficult,  we  are  apt  to  land  in  fanciful  an- 
thropomorphism. Perhaps  we  may  say,  without 
disrespect,  that  it  was  in  great  part  Darwin's 
method,  just  as  the  other  was  Spencer's.  Darwin 
approached  the  naturalist's  problem  from  above, 
Spencer  from  below. 

No  better  illustration  of  Darwin's  wholesome 
anthropomorphism  can  be  found  than  the  cardinal 
idea  of  the  struggle  for  existence.  It  is  an  idea 
borrowed  from  human  life;  it  was  consciously 
suggested  to  Darwin  by  reading  Malthus;  it  was 
subconsciously  suggested  by  the  keen  industrial 
competition,  more  striking — because  more  novel — 
in  Darwin's  day  than  in  ours.  In  human  life 
the  phrase  "  struggle  for  existence  "  is  a  formula 
summing  up  in  three  words  half  the  misery  and 
half  the  happiness  of  mankind.  It  means  that 
when  Nature  has  said  to  man  "  you  must  dip-^ 
he  has  always  answered  back  "  I  will  live." l  \It 
means  that  he  has  fought  with  wild  beasts  and 

1  See  "  The  Kingdom  of  Man,"  by  Sir  E.  Ray  Lankester. 


72         DARWINISM   AND    HUMAN    LIFE 

worsted  them  or  tamed  them,  that  he  has  sifted 
out  the  wholesome  from  the  poisonous  plants,  that 
cowering  and  crouching  for  ages,  he  has  watched 
the  forces  of  nature  till  he  has  mastered  their 
secrets,  that  he  has  been  to  his  fellows  since  the 
beginning  the  strangest  mixture  of  self-assertiveness 
and  sympathy,  that  he  has  kept  up  an  age-long 
endeavour  after  well-being — always  at  his  best 
when  rowing  hard  against  the  stream.^ 

The  formula,  "  struggle  for  existence,"  familiar 
in  human  affairs,  was  used  by  Darwin  in  his 
interpretation  of  organic  life,  and  he  showed  that 
we  gain  clearness  in  our  outlook  on  animate 
nature  if  we  recognise  there,  in  continual  process, 
a  struggle  for  existence  not  merely  analogous 
to,  but  fundamentally  the  same  as  that  which 
goes  on  in  human  life.  He  projected  on  organic 
life  a  sociological  idea,  and  showed  that  it  fitted. 
But  while  he  thus  vindicated  the  relevancy  and 
utility  of  the  sociological  idea  within  the  biological 
realm,  he  declared  explicitly  that  the  phrase 
"  struggle  for  existence "  was  meant  to  be  a 
shorthand  formula,1  summing  up  a  vast  variety 
of  strife  and  endeavour,  of  thrust  and  parry,  of 
action  and  reaction.  The  idea  has  been  better 
realised  by  naturalists  than  by  the  severer  labora- 
tory specialists.  "  It  was  certainly  no  chance," 
Weismann  says,  "  that  the  struggle  for  exist- 
ence first  revealed  itself  to  men  who  had  spent 
the  greater  part  of  their  lives  in  the  open  air." 
Similarly,  Prof.  Poulton  suggests  that  the  main 
reason  why  Huxley  never  appreciated  the  theory 

1  "  For  words  are  wise  men's  counters — they  do  but  reckon  by 
them  ;  but  they  are  the  money  of  fools."  Hobbes,  "  Leviathan," 
Pt.  I.  oh.  iv. 


THE    STRUGGLE   FOR    EXISTENCE        73 

of  natural  selection  was  that  he  had  so  little  of 
the  naturalist's  mood  and  experience. 

DIFFERENT  FORMS  OF  THE  STRUGGLE  FOR 
EXISTENCE. — Some  of  Darwin's  successors  have 
taken  pains  to  distinguish  a  great  many  different 
forms  of  the  struggle  for  existence,  and  this 
kind  of  analysis  is  useful  in  keeping  us  aware  of 
the  complexities  of  the  process.  Darwin  himself 
does  not  seem  to  have  cared  much  for  this  logical 
mapping  out  and  defining ;  it  was  enough  for 
him  to  insist  that  the  phrase  was  used  "in  a 
large  and  metaphorical  sense,"  and  to  give  full 
illustrations  of  its  various  modes.  For  our  present 
purpose  it  is  enough  to  follow  his  example. 

(a)  Struggle  between  Fellows. — When  the  locusts 
of  a  huge  swarm  have  eaten  up  every  green  thing 
they  sometimes  turn  on  one  another.  This  canni- 
balism among  fellows  of  the  same  species — illus- 
trated, for  instance,  among  many  fishes — is  the 
most  intense  form  of  the  struggle  for  existence. 
An  eerie  struggle  occurs  between  sister  embryos 
in  the  egg-capsules  of  the  buckie  and  the  dog- 
whelk  on  the  sea-shore.  This  sort  of  thing  has 
its  close  analogue  in  what  goes  on  between  thick- 
sown  seedlings  of  the  same  kind,  which  compete 
with  one  another  for  room  and  food  and  light. 
The  struggle  does  not  need  to  be  direct  to  be 
real — the  essential  point  is  that  the  competitors 
seek  after  the  same  desiderata  of  which  there  is 
a  limited  supply.  Whether  an  adult  frog  eats 
a  tadpole  of  its  own  kind,  or  a  female  spider 
her  suitor,  or  coral  polyps  compete  for  the  same 
niche,  or  rabbits  for  the  same  scanty  food,  the 
formula  is  the  same  in  all  cases,  and,  apart  from 
chance,  the  result  will  be  the  same — the  survival 


74         DARWINISM   AND    HUMAN   LIFE 

of  those  fittest  for  the  particular  conditions. 
The  struggle  may  be  for  food,  or  foothold,  or 
breathing-space,  or  what  is  sought  after  may  be 
a  luxury,  as  is  seen  in  the  wild  stampede  of  the 
reindeer  when  the  longing  to  visit  the  salt  sea- 
shore becomes  irresistible — many  are  overthrown 
and  trampled  in  the  mad  rush. 

As  an  instance  of  keen  struggle  between  nearly 
related  species,  Darwin  referred  to  the  combats 
of  rats.  The  black  rat  was  in  possession  of  many 
European  towns  before  the  brown  rat  crossed 
the  Volga  in  1727 ;  whenever  the  brown  rat 
arrived  the  black  rat  had  to  go  to  the  wall.  Thus 
at  the  present  day  there  are  practically  no  black 
rats  in  Great  Britain.  Here  the  struggle  for 
existence  is  again  directly  competitive.  It  is 
difficult  to  separate  off  the  struggle  for  food  and 
foothold  from  the  struggle  for  mates,  and  it  seems 
clearest  to  include  here  the  battles  of  the  stags 
and  the  capercailzies,  or  the  extraordinary  lek 
of  the  blackcock — showing  off  their  beauty  at 
sun-rise  on  the  hills. 

(b)  Struggle  between  Foes. — In  the  locust  swarm 
and  in  the  rats*  combats  there  is  competition 
between  fellows  of  the  same  or  nearly  related 
species,  but  the  struggle  for  existence  includes 
much  wider  antipathies.  We  see  it  between  foes 
of  entirely  different  nature,  between  carnivores 
and  herbivores,  between  birds  of  prey  and  small 
mammals.  In  both  these  cases  there  may  be  a 
stand-up  fight,  for  instance  between  wolf  and 
stag,  or  between  hawk  and  ermine;  but  neither 
the  logic  nor  the  biology  of  the  process  is  different 
when  all  the  fight  is  on  one  side.  As  the  lemmings, 
which  have  over-populated  the  Scandinavian 


THE    STRUGGLE   FOR    EXISTENCE        75 

valleys,  go  on  the  march  they  are  followed  by 
birds  and  beasts  of  prey,  which  thin  their  ranks. 
Moreover,  the  competition  between  species  need 
not  be  direct ;  it  will  come  to  the  same  result 
if  both  types  seek  after  the  same  things.  The 
victory  will  be  with  the  more  effective  and  the 
more  prolific. 

In  the  same  way  we  pass  from  the  struggle  of 
similar  seedlings  in  the  over-crowded  garden-plot 
to  the  struggle  of  coarser  with  finer  grasses  after 
a  veldt-fire — in  many  cases  apparently  ending  in 
the  survival  of  the  coarsest. 

(c)  Struggle  with  Fate. — Our  sweep  widens  still 
further,  and  we  pass  beyond  the  idea  of  competition 
altogether,  to  cases  where  the  struggle  for  existence 
is  between  the  living  organism  and  the  inanimate 
conditions  of  its  life — for  instance,  between  birds 
and  the  winter's  cold,  between  aquatic  animals 
and  changes  in  the  water,  between  plants  and 
drought,  between  plants  and  frost — in  a  wide 
sense,  between  Life  and  Fate.1 

THE  STRUGGLE  FOR  EXISTENCE  IN  THE  PLANT 
WORLD. — We  may  be  saved  from  taking  a  narrow 
view  of  the  struggle  for  existence  if  we  emphasise 
the  fact  that  the  concept  must  apply  to  plants 
as  much  as  to  animals.  "  It  has  always  pleased 
me,"  Darwin  said,  "  to  exalt  plants  in  the  scale 
of  organised  beings,"  and  in  his  books  "  The 
Power  of  Movement  in  Plants,"  "  Climbing 

1  We  cannot  here  pursue  the  suggestive  idea  that,  besides  struggle 
between  individuals,  there  is  struggle  between  groups  of  individuals 
— the  latter  most  notably  developed  in  mankind.  Similarly, 
working  in  the  other  direction,  there  is  struggle  between  parts 
or  tissues  in  the  body,  between  cells  in  the  body,  between  equiva- 
lent germ-cells,  and,  perhaps,  as  Weismann  pictures,  between  the 
various  multiplicate  items  that  make  up  our  inheritance. 


76         DARWINISM   AND    HUMAN   LIFE 

Plants,"  and  "  Insectivorous  Plants,"  we  find 
most  interesting  evidence  that  they  are  not  so 
sound  asleep  as  is  often  thought.  Among  the 
insectivorous  plants  we  find  actively  aggressive, 
almost  militant,  forms,  like  the  well-known  Venus 
Fly-trap  and  the  Sundew.  Do  they  struggle 
less  really  than  the  octopus  ?  Has  not  the  Venus 
Fly-trap  more  than  a  hint  of  memory  ?  Yet 
how  impossible  to  draw  the  line  where  aggres- 
siveness ceases !  We  have  to  include  the  pas- 
sive pitcher-plants  and  bladderworts.  Apart  from 
actually  carnivorous  plants  there  are  various 
orchids  that  entrap,  or,  we  may  almost  say, 
visibly  resent  certain  intruding  insects,  and  there 
are  many  common  plants  that  have  deep  moats 
where  unwelcome  visitors  drown,  hedges  of  hairs 
where  they  are  entangled,  sticky  surfaces  where 
they  are  limed. 

There  is  no  bloodshed  among  plants,  but  there 
is  over-crowding,  crushing,  starving,  smothering, 
strangling.  Whether  we  take  two  lichens — each 
a  quaint  partnership  of  Alga  and  Fungus — com- 
peting for  room  to  grow  on  an  exposed  stone, 
or  the  plants  in  the  meadow,  or  the  weeds  in 
the  sluggard's  garden,  or  the  crowded  life  of  the 
jungle,  we  find  clear  evidence  of  competition  for 
space  and  light,  for  food  and  air.  This  has  been 
beautifully  expressed  by  R.  L.  Stevenson,  in  his 
poem  "  The  Woodman'"  : 

Thick  round  me  in  the  teeming  mud 

Brier  and  fern  strove  to  the  blood : 

The  hooked  liana  in  his  gin 

Noosed  his  reluctant  neighbours  in : 

There  the  green  murderer  throve  and  spread, 

Upon  his  smothering  victims  fed, 


THE   STRUGGLE   FOR    EXISTENCE        77 

And  wantoned  on  his  climbing  coil. 

Contending  roots  fought  for  the  soil 

Like  frightened  demons  :    with  despair 

Competing  branches  pushed  for  air. 

Green  conqu    ors  from  overhead 

Bestrode  the  bodies  of  their  dead : 

The  Caesars  of  the  sylvan  field, 

Unused  to  fail,  foredoomed  to  yield : 

For  in  the  groins  of  branches,  lo ! 

The  cancers  of  the  orchid  grow. 

Silent,  as  in  the  listed  ring, 

Two  chartered  wrestlers  strain  and  cling ; 

Dumb  as  by  yellow  Hooghly's  side 

The  suffocating  captives  died ; 

So  hushed  the  woodland  warfare  goes 

Unceasing ;    and  the  silent  foes 

Grapple  and  smother,  strain  and  clasp 

Without  a  cry,  without  a  gasp. 

Here  also  sound  Thy  fans,  0  God, 

Here  too  Thy  banners  move  abroad : 

Forest  and  city,  sea  and  shore, 

And  the  whole  earth,  Thy  threshing-floor ! 

The  drums  of  war,  the  drums  of  peace, 

Roll  through  our  cities  without  cease, 

And  all  the  iron  halls  of  life 

Ring  with  the  unremitting  strife. 

But  as  we  continue  our  illustrations  of  struggle 
among  plants  we  lose  the  competitive  note  alto- 
gether,— in  cases  like  the  desert  plant  with- 
standing exceptional  drought,  and  the  northern 
plant  withstanding  unusually  keen  frost.  No  one 
doubts  that  extremes  of  drought  and  cold,  and 
the  like,  press  upon  the  ceaseless  endeavour  of 
even  vegetable  life,  and  that  the  plants  answer 
back.  They  do  not  take  every  assault  lying 
down. 

ILLUSTRATION  OF  THE  COMPLEXITY  OP  THE 
STRUGGLE  FOR  EXISTENCE. — To  convey  a  broad 


78         DARWINISM   AND    HUMAN    LIFE 

impression  of  the  struggle  for  existence  we 
cannot  do  better  than  refer  to  a  graphic  picture 
drawn  by  Mr.  W.  H.  Hudson  in  his  charming 
"  Naturalist  in  La  Plata."  The  summer  of  1872-3 
in  La  Plata  was  rich  in  sunshine  and  showers ; 
there  was  great  wealth  of  blossom ;  the  humble- 
bees  were  very  abundant ;  and  the  season  was 
also  very  favourable  for  mice  which  devoured  the 
bees.  "  In  autumn  the  earth  so  teemed  with 
mice  that  one  could  scarcely  walk  anywhere 
without  treading  on  them ;  while  out  of  every 
hollow  weed-stalk  lying  on  the  ground  dozens 
could  be  shaken."  They  were  so  abundant  that 
"  the  dogs  subsisted  almost  exclusively  on  them ; 
the  fowls  also,  from  incessantly  pursuing  and 
killing  them,  became  quite  rapacious  in  their 
manner  ;  whilst  the  sulphur  tyrant-birds  (Pitangus) 
and  the  Guira  Cuckoos  preyed  on  nothing  but 
mice."  The  cats  became  wild  hunters ;  "  foxes, 
weasels,  and  opossums  fared  sumptuously  ;  even 
for  the  common  armadillo  (Dasypus  villosus)  it 
was  a  season  of  affluence."  Countless  numbers 
of  storks  and  of  short-eared  owls  came  to  assist 
at  the  general  feast.  The  owls  were  so  numerous 
that  any  evening  after  sunset  Mr.  Hudson  could 
count  forty  or  fifty  hovering  over  the  trees  about 
his  house.  They  became  destructive  to  birds  as 
well  as  mice,  and  although  the  naturalist  shot 
many  to  try  to  reduce  the  havoc  they  were  making 
among  the  ovenbirds,  the  gaps  he  made  were  so 
rapidly  filled  that  he  grew  sick  of  the  cruel  war 
in  which  he  had  hopelessly  joined.  "  A  singular 
circumstance  was  that  the  owls  began  to  breed 
in  the  middle  of  winter."  "  By  August  (1873) 
the  owls  had  vanished,  and  they  had,  indeed, 


THE   STRUGGLE    FOR    EXISTENCE       79 

good  cause  for  leaving.  The  winter  had  been 
one  of  continued  drought ;  the  dry  grass  and 
herbage  of  the  preceding  year  had  been  consumed 
by  the  cattle  and  wild  animals,  or  had  turned 
to  dust,  and,  with  the  disappearance  of  their 
food  and  cover,  the  mice  had  ceased  to  be."  The 
cats  sneaked  back  to  the  houses.  "  It  was  pitiful 
to  see  the  little  burrowing  owls ;  for  these  birds, 
not  having  the  powerful  wings  and  prescient 
instincts  of  the  vagrant  Otus  brachyotus,  were 
compelled  to  face  the  poverty  from  which  the 
others  escaped."  They  became  tame  with  hunger, 
and  so  reduced  as  scarcely  to  be  able  to  fly. 

Fine  weather,  ready  cover,  and  plenty  of  food 
had  allowed  the  mice  to  multiply  beyond  measure, 
but  their  enemies  had  likewise  increased.  As 
the  herbage  disappeared,  multiplication  of  mice 
ceased,  and  the  army  of  enemies  cleared  off  the 
residue  so  thoroughly  that  "  in  spring  it  was 
hard  to  find  a  survivor,  even  in  barns  and  houses." 

This  "  wave  of  life  "  is  one  of  the  most  in- 
structive of  biological  pictures.  It  illustrates  the 
web  of  life,  and  the  variety  of  the  struggle  for 
existence.  A  physical  change  lets  the  stream  of 
life  overflow,  and,  as  the  flood  gathers  momentum, 
it  widens  the  breach  in  its  banks.  One  struggle 
causes  another  struggle.  Flowers  abound,  bees 
abound,  mice  abound,  cats  and  owls  abound,  and 
there  is  struggle  amongst  all.  Diets  are  changed, 
habits  are  changed,  numerical  proportions  are 
changed,  and  then  the  season  changes  and  all 
is  over.  The  mice  are  reduced  to  a  minimum 
and  the  wave  of  life  is  lost  in  the  sand. 

"  The  fact,"  Mr.  Hudson  says,  "  that  species 
tend  to  increase  in  a  geometrical  ratio  makes 


80         DARWINISM   AND   HUMAN    LIFE 

these  great  and  sudden  changes  frequent  in  many 
regions  of  the  earth ;  but  it  is  not  often  they 
present  themselves  so  vividly  as  in  the  foregoing 
instance,  for  here,  scene  after  scene,  is  one  of 
Nature's  silent,  passionless  tragedies  open  before 
us,  countless  myriads  of  highly  organised  beings 
rising  into  existence  only  to  perish  almost  im- 
mediately, scarcely  a  hard-pressed  remnant  re- 
maining after  the  great  reaction  to  continue  the 
species." 

KEASONS  FOR  THE  STRUGGLE  FOR  EXISTENCE. — 
The  reasons  for  the  struggle  for  existence  among 
animals  and  plants  are  fundamentally  the  same 
as  those  which  lie  behind  our  own  human  struggle 
and  endeavour.  "  Why  do  the  people  thus  strive 
and  cry  ?  "  Goethe  asked,  and  gave  the  answer, 
"  They  will  have  food,  they  will  have  children, 
and  bring  them  up  as  well  as  they  can."  So  it 
is  with  other  living  creatures — their  twofold, 
never-ending  business  is  to  care  for  themselves 
and  to  care  for  others.  It  has  been  said  that 
hunger  and  love  solve  the  world's  problems,  and 
this  is  true  if  we  take  a  wide  enough  view  of  these 
notable  words. 

(a)  One  reason  for  struggle  is  to  be  found  in  the 
tendency  to  over-population.  The  river  of  life 
is  always  tending  to  overflow  its  banks.  Struggle 
is  the  safety-valve  against  the  internal  pressure 
of  rapidly  increasing  population.  Wallace  quotes 
Kerner  to  the  effect  that  a  common  British  weed 
(Sisymbrium  sophia)  often  has  three-quarters  of 
a  million  seeds ;  if  all  grew  to  maturity  for  only 
three  years  the  whole  of  the  land-surface  of  the 
globe  would  not  hold  them.  An  annual  plant 
with  only  two  seeds  would  be  represented  by 


THE   STRUGGLE    FOR   EXISTENCE       81 

1,048,576  in  the  twenty-first  year.  "  A  bacillus 
less  than  •§•  stoth  of  an  inch  in  length  multiplies, 
under  normal  conditions,  at  a  rate  that  would 
cause  the  offspring  of  a  single  individual  to  fill 
the  ocean  to  the  depth  of  a  mile  in  five  days  " 
(H.  E.  Cramp  ton).  "  The  cholera  bacillus  can 
duplicate  every  twenty  minutes,  and  might  thus 
in  one  day  become  5,000,000,000,000,000,000,000, 
with  the  weight,  according  to  the  calculations  of 
Cohn,  of  about  7,366  tons.  In  a  few  days,  at  this 
rate,  there  would  be  a  mass  of  bacteria  as  big 
as  the  moon,  huge  enough  to  fill  the  whole  ocean  " 
(Saleeby). 

The  slowest  breeder  among  mammals  is  the 
elephant ;  it  is  supposed  to  rear  one  young  one 
every  ten  years,  but,  as  it  lives  to  more  than  a 
hundred,  Darwin  calculated  that  in  750  years  each 
pair  would,  if  all  their  offspring  lived  and  bred, 
be  the  ancestor  of  nineteen  millions.  The  lemmings 
in  the  Scandinavian  valleys  become  periodically  so 
numerous  that  they  eat  up  every  plant,  and  must 
march  or  starve.  The  bands  become  an  army  which 
devastates  as  it  goes,  till  their  problem  is  solved 
in  the  waves  of  the  Baltic  or  the  North  Sea. 

A  cod  has  two  million  eggs,  they  say ;  if  these  all 
developed  into  cods  there  would  soon  be  no  more 
fishing.  An  oyster  may  have  sixty  million  eggs, 
and  the  average  American  yield  is  sixteen  millions. 
If  all  the  progeny  of  one  oyster  survived  and 
multiplied,  its  great-great-grand-children  would 
number  sixty-six  with  thirty-three  noughts  after 
it,  and  the  heap  of  shells  would  be  eight  times  the 
size  of  the  world. 

Huxley  calculated  that  if  the  descendants  of  a 
single  green-fly  all  survived  and  multiplied  they 

6 


82         DARWINISM   AND    HUMAN    LIFE 

would,  at  the  end  of  summer,  weigh  down  the 
population  of  China. 

The  common  house-fly  lays  eggs  in  batches  of 
120  to  150  at  a  time,  and  may  lay  five  or  six  of 
these  batches  during  its  life — of  about  three  weeks 
in  very  hot  weather.  At  the  end  of  summer,  if  all 
developed,  and  if  there  were  six  generations,  the 
progeny  of  a  single  pair,  pressed  together  into  a 
solid  mass,  would  occupy  a  space  of  something  like 
a  quarter  of  a  million  cubic  feet,  allowing  200,000 
flies  to  a  cubit  foot.  There  is  no  real  increase, 
hence  the  mortality  must  be  prodigious. 

The  intensity  of  the  struggle  can  be  inferred 
from  the  rate  of  increase.  If  there  is  slow  multi- 
plication and  yet  no  falling  off  in  the  number  of 
adults,  there  is  no  keen  struggle  for  existence.  If 
there  is  rapid  multiplication  and  yet  no  increase 
in  the  number  of  adults,  there  must  be  a  keen 
struggle  for  existence.  It  is  useful  to  think  over 
the  simple  equation  :  the  number  produced  minus 
the  number  eliminated  equals  the  normal  number 
of  adults. 

(6)  Another  reason  follows  from  the  pattern  of 
the  web  of  life — there  are  nutritive  chains,  one 
organism  depending  on  another  for  its  food-supply. 
Indeed,  the  struggle  that  strikes  us  most  is  that 
which  follows  from  the  obvious  fact  that  many 
animals  prefer  to  be  carnivorous.  There  is  a  good 
deal  of  the  conjugation  of  the  verb  "  To  eat "  in 
life,  and  the  objection  to  be  eaten  is  as  natural 
to  some  animals  as  the  desire  to  eat  is  to  others. 

(c)  A  third  reason  for  struggle  is  to  be  found 
in  the  irregular  changefulness  of  the  physical 
environment.  Give  an  animal  time,  and  it  may 
become  marvellously  well  adapted  to  its  surround- 


THE   STRUGGLE   FOR    EXISTENCE        83 

ings,  as  hand  to  glove ;  but  when  the  surroundings 
change  the  adaptation  is  gone.  In  some  cases, 
indeed,  the  living  creature  is  adapted  to  change 
with  the  changes  of  its  surroundings :  turning  white 
in  winter,  for  instance,  like  the  mountain-hare  and 
the  ptarmigan.  But  when  the  outer  world  changes 
irregularly,  then  the  shoe  pinches.  The  living 
creature  must  accept  defeat  or  struggle,  and  its 
struggle  may  bring  it  success  until  a  constitutional 
variation  in  the  right  direction  has  time  to  establish 
itself. 

(d)  Another  reason  for  struggle  is  often  over- 
looked— namely,  the  self-assertiveness  of  the 
vigorous  animal.  The  lusty  creature  tends  to  be 
a  hustler.  It  elbows  its  way  through  the  crowd, 
jostling  its  neighbours.  Even  the  plant  pushes 
and  obstructs,  ensnares  and  strangles,  stings  and 
kills. 

RESULTS  OP  THE  STRUGGLE  FOR  EXISTENCE. — 
There  are  three  chief  results  of  the  ubiquitous 
struggle  for  existence. 

(A)  In  the  first  place,  there  may  be  a  reduction 
in  numbers  which  relieves  the  pressure  of  popula- 
tion without  directly  making  for  progress.     Out 
of  533  larvae  of  the  large  garden  white  butterfly 
collected  by  Prof.  Poulton,  422  died  from  ichneu- 
mon   grubs:    four   out   of    every    five — a   great 
mortality.    But  since  there  was  no  evidence  that 
the  survivors  were  saved  by  being  the  possessors  of 
some  peculiarity  which  those  eliminated  lacked,  the 
thinning  had  no  evolutionary  importance.     It  was 
merely  fortuitous  or  indiscriminate  elimination. 

(B)  In  the  second  place,  it    may  be  that  the 
organism  is  driven,  by  the  pressure  of  the  struggle, 
to  seek  out  a  new  habitat,  to  choose  a  more  appro- 


84         DARWINISM   AND    HUMAN   LIFE 

priate  environment,  or,  what  comes  to  the  same 
thing,  to  form  a  new  habit.  From  the  beginning, 
necessity  has  been  the  mother  of  invention.  For 
animals,  as  for  man,  the  exploration  of  new  terri- 
tory has  been  a  constantly  recurrent  result  of  the 
struggle  for  existence,  and  one  of  the  most  im- 
portant. The  open-air  naturalist  is  familiar  with 
the  way  in  which  nearly  related  species  fill  slightly 
different  corners  in  the  same  crowded  area.  It  is 
interesting,  also,  to  think  of  the  gradual  peopling  of 
strange  habitats,  such  as  the  abysses  of  the  ocean, 
the  dark  caves,  and  under  the  ground ;  or  how 
fishes  come  ashore,  and  mammals  get  into  the  air, 
and  crabs  go  up  the  mountains. 

(c)  In  the  third  place,  there  may  be  discriminate 
elimination  of  the  less  fit  to  the  given  conditions, 
and  it  is  this  result  that  has  most  evolutionary 
interest.  The  black  rat's  territory  is  invaded  by 
the  brown  rat,  and  soon  there  is  only  brown  rat. 
Probably  Kropotkin  is  right  in  suggesting  that 
this  case  is  less  simple  than  Darwin  supposed,  for 
the  arrival  of  a  second  rat  made  man  wake  up, 
and  the  weaker  species  yielded  first.  But  there 
is  evidence  enough  to  lead  us  to  believe  that  the 
struggle  between  brown  rat  and  black  rat  leads 
to  the  rapid  extermination  of  the  black.  From 
this  extreme  case  we  find  every  possible  gradation, 
till  all  we  can  say  is  that  the  less  fit  are  slightly 
handicapped  in  the  race  of  life.  But  if  the  slight 
handicapping  tells  at  all — and  tells  consistently — 
as  regards  length  and  vigour  of  life,  or  number  and 
vigour  of  offspring,  then  it  will  serve  as  a  selective 
agent. 

It  is  very  important  to  realise  that  the  struggle 
for  existence  may  select  without  rapidly  killing  off 


THE    STRUGGLE    FOR    EXISTENCE        85 

the  less  fit.  If  it  mean  that  the  less  fit  have  a  more 
difficult  life  and  do  not  live  so  long,  if  it  mean  that 
they  have  smaller  and  less  vigorous  families,  if  it 
mean  that  the  parents  are  harassed  so  that  they 
cannot  give  the  offspring  the  best  available  start, 
then  it  will,  in  the  long  run,  work  out  to  the  same 
result  as  if  the  less  fit  had  come  to  a  rapid  violent 
end.  The  advantageous  character  that  the  fit 
variant  possesses  may  be  of  survival- value,  although 
the  absence  of  it  does  not  mean  the  sudden  death 
of  the  less  fit. 

The  elimination  of  the  less  fit  may  have  a  con- 
servative influence,  without  resulting  in  any  pro- 
gressive change.  It  may  keep  the  race  up  to  an 
established  standard.  But  this  is  precisely  the 
same  kind  of  process  as  that  which  results  in 
progressive  adaptation,  and  should  not  be  separated 
off.  It  need  hardly  be  said  that  when  we  find  a 
state  of  affairs  where  slackness  is  tolerated,  it 
means  a  temporary  resting  on  the  oars.  Among 
434  toads  taken  from  the  same  place,  Prof.  W.  E. 
Kellicott  found  5  per  cent,  with  injuries  and  3'68 
per  cent,  with  abnormalities,  mostly  disadvantage- 
ous. The  conditions  of  life  were  peculiarly  easy, 
there  was  abundant  food,  there  were  few  enemies, 
there  were  readily  available  means  of  protection 
and  concealment. 

BREADTH  OF  THE  DARWINIAN  CONCEPT  OF  THE 
STRUGGLE  FOR  EXISTENCE. — There  are  many  au- 
thorities who  insist  that  what  Darwin  particularly 
and  mainly  meant  was  the  struggle  between 
organisms  of  the  same  kind.  Thus  Weismann 1 
writes :  The  "  struggle  for  existence,"  which 

1  "  Darwin  and  Modern  Science."  Edited  by  A.  C.  Seward, 
Cambridge  (1909),  p.  20 


86         DARWINISM   AND    HUMAN    LIFE 

Darwin  regarded  as  taking  the  place  of  the  human 
breeder  in  free  nature,  is  not  a  direct  struggle  be- 
tween carnivores  and  their  prey,  but  is  the  assumed 
competition  for  survival  between  individuals  of 
the  same  species,  of  which,  on  an  average,  only 
those  survive  to  reproduce  which  have  the  greatest 
power  of  resistance,  whilst  the  others,  less  favour- 
ably constituted,  perish  early."  1 

Here,  however,  as  in  not  a  few  other  instances, 
Darwin  is  broader  than  many  Darwinians.  Al- 
though one  of  the  sections  in  chapter  iii.  of 
"  The  Origin  of  Species  "  is  headed  "  Struggle  for 
Life  most  Severe  between  Individuals  and  Varieties 
of  the  same  Species,"  the  evidence  given  hardly 
justifies  the  title,  and,  in  any  case,  another  section 
is  headed  "  The  Term,  Struggle  for  Existence,  used 
in  a  Large  Sense."  In  writing  to  Hooker  in  1856, 
he  said :  "  The  slight  differences  selected,  by  which 
a  race  or  species  is  at  last  formed,  stand  in  a  far 
more  important  relation  to  its  associates  than  to 
external  conditions  " ;  but  there  are  many  passages 
in  "  The  Origin  of  Species "  which  express  the 
view  that  the  struggle  for  existence  as  the  method 
of  Nature's  sifting  includes  very  much  more  than 
internecine  competition  between  fellows.  "I  should 
premise,"  he  says,  "  that  I  use  this  term  ["  struggle 
for  existence  "]  in  a  large  and  metaphorical  sense, 
including  dependence  of  one  being  on  another, 
and  including  (which  is  more  important)  not  only 
the  life  of  the  individual,  but  success  in  leaving 
progeny." 

1  The  same  view  is  expressed  by  Haeckel  and  Ray  Lankester, 
but  I  am  glad  to  find  that,  in  his  scholarly  and  judicial  "  Handbook 
of  Darwinism,"  Prof.  L.  Plate  interprets  Darwin's  conclusions 
and  the  state  of  affairs  in  nature  in  much  the  same  way  as  I  have 


THE    STRUGGLE   FOR    EXISTENCE       87 

The  position  which  we  are  seeking  to  define  and 
defend  is  this.  The  concept  "  struggle  for  exist- 
ence "  is  wider  than  is  suggested  by  the  words 
taken  literally.  It  is  a  function  of  many  in- 
dependent variables.  It  expresses  the  reaction  of 
living  creatures  to  their  limitations  and  difficulties. 
It  means  that  living  is  rarely  drifting,  except  for 
parasites.  The  physical  world  is  careless  of  life; 
there  is  an  extraordinary  abundance  of  life ;  the 
river  is  always  surging  up  to  its  embankments ; 
love  calls,  hunger  calls,  and  there  is  often  no  satis- 
faction ;  there  are  many  critical  moments  in  growth 
and  development,  many  risks  of  falling  through 
holes  in  the  Mirza  bridge ;  the  living  creature  has 
a  will  of  its  own — a  will  to  live, — all  this,  and 
more,  may  be  usefully  condensed  in  the  formula 
"  struggle  for  existence." 

Our  thesis  is  that  we  have  the  struggle  for  exist- 
ence wherever  living  creatures  press  up  against 
limiting  conditions ;  wherever  living  creatures,  with 
their  powers  of  growing  and  multiplying,  thrusting 
and  parrying,  changing  and  being  changed,  do  in 
any  way  say,  "  We  will  live/' 

The  living  creature  is  by  its  very  essence  asser- 
tive. If  it  cannot  do  anything  else  it  will  multiply. 
Life  is  an  endeavour ;  it  expands,  it  intrudes  itself, 
it  protests  against  limitations.  One  living  creature 
presses  upon  another,  competes  with  another,  eats 
another.  And  for  all  this  thrust  and  parry  between 
living  creatures  and  their  limitations  we  use  the 
formula-phrase  "struggle  for  existence."  Surely 
Darwin  had  this  broad  conception  vividly  in  mind 
when  he  used  that  strange  metaphor :  "  Nature 
may  be  compared  to  a  surface  on  which  rest 
ten  thousand  sharp  wedges  touching  each  other 


88         DARWINISM   AND    HUMAN   LIFE 

and  driven  inward  by  incessant  blows  " — the  idea 
being  that  any  wedge  that  was  relieved  from 
blows  would  at  once  rise  above  the  rest.  But 
the  comparison  to  wedges  is  inadequate;  we 
have  to  think  of  living  wedges  with  a  will  of 
their  own — a  will  to  rise,  and  then  we  have  got 
nearer  the  idea  of  the  struggle  for  existence. 
The  same  idea  is  suggested  by  Darwin's  extra- 
ordinary sentence  :  "  It  may  metaphorically  be 
said  that  natural  selection  is  daily  and  hourly 
scrutinising  throughout  the  world  the  slightest 
variations." 

THE  OTHER  SIDE  OP  THE  STRUGGLE  FOR  EXIST- 
ENCE.— If  we  are  right  in  our  wide  interpretation 
of  the  concept  "struggle  for  existence,"  which 
we  maintain  to  be  Darwin's,  though  many  biolo- 
gists, such  as  Sir  E.  Ray  Lankester,  say  it  is  not, 
then  we  can  pass  in  a  more  logical  way  than  here- 
tofore to  what  has  sometimes  been  called  the  other 
side  of  the  struggle  for  existence :  to  a  recognition  of 
the  love  of  mates,  parental  sacrifice,  filial  affection, 
the  kindliness  of  kindred,  gregariousness,  sociality, 
co-operation,  mutual  aid,  and  altruism  generally. 
These  are  facts  of  life,  though  we  may  differ  as  to 
the  precise  psychological  terms  to  be  used  in 
describing  them.  The  business  of  life,  all  through, 
includes  care  for  others  as  well  as  care  for  self.  As 
Herbert  Spencer  says  :  "  If  we  define  altruism  as 
being  all  action  which,  in  the  normal  course  of 
things,  benefits  others  instead  of  benefiting  self, 
then,  from  the  dawn  of  life,  altruism  has  been  no 
less  essential  than  egoism.  Though  primarily  it 
is  dependent  on  egoism,  yet  secondarily  egoism 
is  dependent  on  it."  "  Self-sacrifice  is  no  less 
primordial  than  self-preservation."  As  has  been 


THE    STRUGGLE   FOR   EXISTENCE        89 

well  said :  "  The  purely  self-seeking  animal  has 
been  found  to  be  a  fiction,  like  that  of  the 
economic  man  "  (Norman  Wilde). 

Our  position  is  that,  instead  of  making  an  anti- 
thesis between  "  struggle  for  others  "  and  "  struggle 
for  self,"  it  is  clearer  to  recognise  that  both  may  be 
included  in  the  rubric  of  reaction  of  self-assertive 
living  creatures  against  the  difficulties  and  limita- 
tions of  environing  conditions.  In  many  cases  a 
kin-instinct  is  as  well  denned  as  a  self -preservative 
instinct,  and,  in  face  of  difficulties  and  limita- 
tions, a  solution  may  be  found  along  either  line 
or  along  both.  The  world  is  indeed  the  abode 
of  the  strong,  but  it  is  also  the  home  of  many 
feeble  folk  who  make  up  in  love  what  they  lack 
in  strength. 

MUTUAL  AID. — Kropotkin  has  done  real  service 
to  science  by  showing,  in  detail,  how  much  there 
is  of  mutual  aid  among  animals.  There  are  some 
genuine  societies,  where  the  whole  is  more  than  the 
sum  of  its  parts  and  sometimes  acts  as  a  unity. 
Ants  are  little  people,  and  all  the  world  is  against 
them ;  in  facing  their  limitations — which  is  what 
"  struggle  "  means — they  have  found  a  solution 
in  sociability,  and  they  are  dreaded  by  much 
stronger  insects.  Every  one  knows  that  some 
species  of  ants  go  to  war.  But  our  outlook  on 
nature  should  take  its  colour  not  only  from  the 
warfare,  but  also  from  the  self -subordination  which 
the  whole  life  of  the  ant-hill  illustrates.  In  many 
species  it  seems  to  be  a  law  of  the  hill  that  an  ant 
with  a  full  crop  must  never  refuse  to  feed  a  hungry 
comrade. 

There  is  something  very  suggestive  in  an  ob- 
servation of  Hudson's  in  regard  to  social  and 


90         DARWINISM   AND    HUMAN   LIFE 

sociable  animals  higher  up  in  the  scale,  the  Vis- 
cachas — burrowing  rodents  of  South  America. 
When  the  farmer  destroys  a  viscacha  burrow  and 
buries  the  inhabitants  under  a  heap  of  earth,  other 
viscachas,  coming  from  a  distance — for  village 
often  visits  village — dig  out  those  that  are  buried 
alive.  There  are  thousands  of  similar  facts,  which 
go  to  show  that  there  is  much  more  in  the  animal 
world  than  a  Hobbesian  warfare — each  for  himself 
and  extinction  take  the  hindmost. 

Besides  animal  societies  in  the  stricter  sense 
there  are  many  flocks  and  herds — gregarious  rather 
than  social  creatures ;  and  what  we  know  of  their 
mode  of  life,  though  it  is  not  nearly  so  precise  as  it 
ought  to  be,  warrants  us  in  saying  that  the  vul- 
garisation of  the  Darwinian  picture  of  the  struggle 
for  existence  is  inaccurate.  There  is  an  ugly 
proverb  which  says  that  a  wolf  is  a  wolf  to  other 
wolves,  but  Kipling's  zoology  is  finer :  there's  a 
law  of  the  pack  which  means  self-subordination. 
We  do  not  associate  kites  and  vultures  with  fine 
feelings,  but  the  Brazilian  kite  is  said  to  summon 
its  friends  to  the  feast  (when  it  is  big  enough),  and 
one  of  the  strongest  vultures  is  called — not  without 
good  reason — the  sociable  vulture. 

There  are  instances  of  co-operation  among 
animals  neither  social  nor  gregarious ;  thus  a  dozen 
burying  beetles  may  combine  to  transport  a  dead 
bird  to  soft  ground.  Every  one  knows  that  little 
birds,  like  wagtails,  will  combine  to  drive  off  a  falcon, 
and  there  are  many  records  of  the  frequent  disap- 
pointment of  birds  of  prey  when  they  visit  the 
lake-side  crowded  with  ducks  and  terns  and 
plovers.  It  is  quite  certain  that  the  battle  is  not 
always  to  the  strong.  Another  striking  fact  is  the 


THE    STRUGGLE   FOR    EXISTENCE        91 

social  character  of  migration  in  the  case- of  many 
birds  that  usually  live  alone. 

Besides  sociality,  gregariousness,  and  co-opera- 
tion, there  are  the  associations  of  the  pair  and  the 
family,  which  evidently  include  much  more  than 
squabbling  round  the  platter.  The  struggle  for 
existence  includes,  as  Darwin  emphasised,  "  suc- 
cess in  leaving  progeny."  MacgiUivray  found  two 
thousand  feathers  in  the  nest  of  the  long-tailed  tit. 

It  goes  without  saying  that  mutual  aid  pays, 
and  pays  because  there  is  a  universal  struggle  for 
existence.  We  do  not  wish,  therefore,  to  complicate 
the  issue  with  psychological  questions  of  egoism 
and  altruism,  self -regarding  and  other-regarding; 
nor  do  we  wish  to  make  an  antithesis  between 
mutual  aid  and  mutual  struggle  ;  our  point  is  that 
within  the  wide  concept  of  Struggle — or  Reaction  to 
Limitations — there  is  included  mutual  aid,  and  that 
this  mode  of  solution  is  attended  with  success — a 
success  which  is  more  than  survival,  for  it  spells 
progress  as  well.  As  Kropotkin  says:  "Mutual 
aid  leads  to  mutual  confidence,  the  first  condition 
for  courage,  and  to  individual  initiative,  the  first 
condition  for  intellectual  progress."  The  intel- 
ligence of  the  social  birds,  like  rooks,  parrots,  and 
cranes,  has  been  the  subject  of  admiration  since 
natural  history  began. 

Let  us  get  away  from  mere  words  and  into 
contact  with  facts.  Animals  get  hungry,  they 
seek  their  food,  they  endeavour  to  catch  what  often 
endeavours  not  to  be  caught,  they  compete  with 
others  who  endeavour  to  catch  the  same  elusive 
prey,  they  have  also  to  keep  an  eye  on  those  who 
are  seeking  to  catch  them  while  they  are  seeking 
to  catch  something  else,  and  meanwhile  they  have 


92         DARWINISM   AND    HUMAN   LIFE 

to  struggle  to  keep  their  foothold  amid  the  storm 
of  the  careless  physical  environment.  There  are 
also  struggles  for  mates  and  for  the  sake  of  off- 
spring. Which  of  these  endeavours  is  the  struggle 
for  existence  ?  Each  and  all.  For  the  real  mean- 
ing of  the  phrase  is  to  be  found,  not  in  picturing 
this  or  that  kind  of  struggle  or  endeavour,  but 
rather  in  the  general  idea  of  living  organisms 
asserting  themselves  against  limitations  and  diffi- 
culties, partly  no  doubt  due  to  their  immediate 
competitors  of  the  same  kin  or  even  family,  but 
by  no  means  restricted  to  this. 

OUT  thesis  is  that  progress  depends  on  much 
more  than  a  squabble  around  the  platter  ;  that  the 
struggle  for  existence  is  far  more  than  an  inter- 
necine competition  at  the  margin  of  subsistence ; 
that  it  includes  all  the  multitudinous  efforts  for  self 
and  others  between  the  poles  of  love  and  hunger ; 
that  it  comprises  all  the  endeavours  of  mate  for 
mate,  of  parent  for  offspring,  of  kin  for  kin,  as  well 
as  every  detail  of  self-assertiveness  ;  that  existence 
for  many  an  animal  means  the  well-being  of  a 
socially  bound  or  kin-bound  organism  in  a  social 
milieu  ;  that  egoism  is  not  satisfied  until  it  becomes 
altruistic. 

APPLICATION  OF  THE  CONCEPT  TO  HUMAN  LIFE. 
— What  has  the  Darwinian  conception  of  the 
struggle  for  existence  to  do  with  human  life  ? 

(1)  If  Nature  has  any  particular   word  to  say 
to  man  that  word  is  Endeavour.    All  through  the 
ages  we  may  see  Nature's  condemnation  of  "  the 
unlit  lamp  and  the  ungirt  loin."    Nature  is  all  for 
efficiency,  and  down  on  slackness. 

(2)  It  has  to  be  admitted,   however,  that,  at 
juncture  after  juncture,  Nature  offers  the  alterna- 


THE   STRUGGLE    FOR    EXISTENCE        93 

tive  of  parasitism,  and  there  are  thousands  of  living 
creatures  that  have  followed  this  line  of  least  re- 
sistance with  its  reward  of  adult  safety  and  complete 
material  well-being,  with  its  nemesis  of  degeneracy. 
To  man  also  this  alternative  is  offered,  and  it  is 
not  infrequently,  in  part  at  least,  accepted,  both 
by  lower  and  by  higher  stocks,  and  always  with 
inevitably  attendant  dangers.  Let  us  recall  Mere- 
dith's verse : 

Behold  the  life  of  ease,  it  drifts. 

The  sharpened  life  commands  its  course : 

She  winnows,  winnows  roughly,  sifts, 

To  dip  her  chosen  in  her  source. 

Contention  is  the  vital  force 

Whence  pluck  they  brain, — her  prize  of  gifts. 

(3)  As  among  animals,  so  among  men,  disturb- 
ances of  equilibrium  and  conflict  of  interests  bring 
about  struggle,  and  there  are  always  two  chief  lines 
of  solution  (besides  that  of  partial  parasitism). 
The  one  is  increased  intensity  of  competition  ;  the 
other  is  increased  combination  and  mutual  aid. 
From  the  biologist's  point  of  view  it  is  important 
to  make  clear  that  Nature  has  rewarded  both  these 
lines  of  solution  with  survival,  and  that  the  line 
of  mutual  aid  and  sociality  has  been  especially 
justified  by  psychical  progress.    We  may  take  it 
that,  as  it  has  been  in  the  past,  survival  and  pro- 
gress will  continue   to  be  the   rewards  of   those 
nations  in  which  there  is  not  only  valour  in  com- 
petition (more  and  more  shifted  from  the  battle- 
fields), but  the  virtue  of  loyal  subordination  of 
individual  to  communal  interests. 

(4)  With  the  spread  of  civilisation  the  character 
of  the  struggle  for  existence    among    men    has 


94         DARWINISM   AND    HUMAN    LIFE 

greatly  changed,  becoming  less  and  less  literal,  less 
and  less  sustained.  It  is  seldom  allowed  to  work 
out  to  a  finish,  as  it  does  in  the  animal  world.  As 
this  is  apt  to  result  in  a  state  of  affairs  in  which 
the  superior  are  defrauded  of  the  rewards  of  superi- 
ority and  the  inferior  are  not  mulcted  for  their 
inferiority — an  unnatural  state  of  affairs — it  be- 
hoves man  to  secure  that  the  literal  struggle  for 
existence  is  replaced  by  an  endeavour  after 
well-being,  which  will  continue  in  a  subtler,  more 
rational,  more  humane  form  the  automatic  singling 
and  sifting  which  goes  on  in  Nature. 


CHAPTER  IV 

THE  RAW  MATERIALS  OF 
EVOLUTION 


CHAPTER  IV 

THE  RAW  MATERIALS  OF  EVOLUTION 

Organic  Progress  Primarily  depends  on  Variability — Darwin's  Posi- 
tion— Progress  since  Darwin's  Day  in  Regard  to  Variation — 
Variations  more  Abundant  than  even  Darwin  supposed — 
Proportion  between  Frequency  and  Amount  of  Variations 
— Correlation  of  Variations — Brusque  Variations  more  Frequent 
than  was  formerly  supposed — Discontinuous  Variations — 
Mutations — Darwin's  Position  in  Regard  to  Mutations — Origin 
of  Variations — Germinal  Selection — Variational  Stimuli — 
Modifications  or  Acquired  Characters — Indirect  Importance  of 
Modifications  —  Modification-Species  —  Individual  Plasticity — 
Relation  to  Human  Life. 

ORGANIC  PROGRESS  PRIMARILY  DEPENDS  ON 
VARIABILITY. — The  most  difficult  problem  in  bio- 
logy— part  of  the  persisting  mystery  of  life  itself — 
is  the  innate  changefulness  which  we  often  see 
manifested  in  a  family,  a  herd,  or  a  seed-plot,  when 
we  compare  one  generation  with  another.  Of  how 
much  interest  and  importance  is  this  changefulness ! 
for  it  is  among  the  inborn  variations  of  living 
creatures  that  we  find  the  raw  materials  of  evolu- 
tion. 

Evolution  implies  change — change  along  a  defi- 
nite line,  and  it  also  implies  a  certain  continuity 
throughout  the  change.  Individual  development, 
the  growing  of  the  mustard-seed  into  the  greatest 
of  herbs,  the  "  minting  and  coining  of  the  chick 
out  of  the  egg,"  is  progressive  change  in  which  the 

97  7 


98         DARWINISM   AND    HUMAN   LIFE 

continuity  is  one  of  personal  identity.  In  organic 
evolution  the  continuity  is  racial,  not  individual ; 
but,  as  in  development,  there  is  progress  in  the  wide 
sense.  It  may  be  up  or  down,  for  the  better  or  for 
the  worse,  measured  by  certain  standards,  but 
progress  of  some  sort  is  implied  in  the  concept  of 
evolution,  and  it  is  with  the  raw  materials  of 
progress  that  we  are  now  concerned.  The  interest 
of  this  inquiry  is  enhanced  by  the  fact  that,  through- 
out the  ages,  life  has  been  on  the  whole  slowly 
on  the  upgrade,  and  that  among  animals  there  has 
been  a  gradual  emergence  of  greater  control  and 
more  freedom,  of  a  fuller  life  and  higher  intelligence. 
DARWIN'S  POSITION. — Darwin  started  from  the 
admitted  fact  of  life  that  offspring  are  often 
innately  different  from  one  another  and  from 
their  parents.  Through  his  study  of  species — 
which  began  in  his  boyish  beetle-collecting  and 
went  on  to  his  eight  years'  work  on  barnacles — 
he  had  become  aware  of  the  fountain  of  change 
in  living  creatures,  and  he  strengthened  his 
impression  by  patiently  accumulating  facts  in 
regard  to  the  variability  of  domesticated  animals 
and  cultivated  plants.  In  his  original  1858  essay, 
and  in  the  "  Origin  of  Species  "  (1859),  he  recog- 
nised two  kinds  of  hereditary  variations  :  (1)  large 
"  single  variations,"  or  "  sports,"  which  occur 
rarely  and  result  in  individuals  conspicuously 
different  from  the  type  of  the  species ;  and  (2), 
slight  "  individual  variations,"  which  are  of 
frequent  occurrence,  distinguishing  child  from 
parent,  brother  from  sister,  or  cousin  from  cousin. 
He  was  much  interested  in  the  large  single  varia- 
tions, such  as  occurred  in  the  origin  of  copper-beech 
and  weeping  willow,  but — true  to  the  influence 


THE   RAW    MATERIALS    OF    EVOLUTION    99 

of  Lyell — he  came  to  the  conclusion  that  the 
minute  ubiquitous  "  individual  variations  "  were 
by  far  the  more  important.  Fleeming  Jenkin, 
Professor  of  Engineering  in  Edinburgh,  pointed 
out  that  single  large  peculiarities  would  be  likely 
to  be  swamped  by  inter-crossing,  and  this  criticism 
had  so  much  weight  with  Darwin  that  he  ceased 
to  attach  importance  to  the  larger  divergences, 
and  found  his  raw  material  in  what  he  called 
"  individual  variations."  "  The  more  I  work," 
he  said,  "  the  more  I  feel  convinced  it  is  by  the 
accumulation  of  such  extremely  slight  variations 
that  new  species  arise." 

In  reference  to  both  sports  and  small  variations, 
Darwin  used  the  terms  "  indefinite  "  and  "  spon- 
taneous," to  distinguish  them  from  "  definite 
variations,"  which  are  now  called  somatic  modifica- 
tions— i.e.  definite  and  direct  results  of  environ- 
mental or  functional  changes.  Darwin  believed 
in  the  occasional  transmissibility  of  these  "  definite 
variations,"  and  in  so  doing  he  agreed  with 
Lamarck,  whose  work  he  does  not  seem  to  have 
adequately  appreciated. 

PROGRESS  SINCE  DARWIN'S  DAY  IN  REGARD  TO 
VARIATION. — While  we  must  still  confess,  with 
Darwin,  that  in  regard  to  the  causes  of  variation 
our  ignorance  is  immense,  we  have  also  to  recognise 
that,  in  several  directions,  there  is  progress  to 
report.  For  some  time  after  the  publication  of 
"  The  Origin  of  Species "  more  attention  was 
given  to  the  directive  than  to  the  originative  factors 
in  evolution.  The  idea  of  selection  fascinated 
naturalists,  and  it  was  too  much  the  custom  simply 
to  postulate  variability  to  meet  the  demands  of 
particular  problems.  Life  is  so  abundant  and 


100       DARWINISM   AND   HUMAN   LIFE 

so  Protean  that  biologists  tended  to  draw  upon 
the  variability  account  as  if  there  was  no  limit 
to  it,  scarce  waiting  to  see  whether  their  cheques 
were  honoured.  A  lesson  might  have  been  taken 
from  Darwin's  painstaking  study  (1868)  of  varia- 
tions in  domesticated  animals  and  cultivated 
plants,  or  from  Mr.  J.  A.  Allen's  pioneer  work 
(1871)  in  measuring  American  birds,  but  the 
vice  of  simply  postulating  variations  when  they 
were  wanted  for  theoretical  purpose  persisted 
and  has  been  wide-spread  for  fifty  years. 

In  the  preface  to  his  "  Materials  for  the  Study 
of  Variation  "  (1894),  Bateson  wrote :  "  We  are 
continually  stopped  by  such  phrases  as,  '  if  such 
and  such  a  variation  then  took  place  and  was 
favourable/  or,  '  we  may  easily  suppose  circum- 
stances in  which  such  and  such  a  variation,  if 
it  occurred,  might  be  beneficial/  and  the  like. 
The  whole  argument  is  based  on  such  assumptions 
as  these — assumptions  which,  were  they  found 
in  the  arguments  of  Paley  or  of  Butler,  we  could 
not  too  scornfully  ridicule.  ...  If  we  had  before 
us  the  facts  of  variation  there  would  be  a  body 
of  evidence  to  which,  in  these  matters  of  doubt, 
we  could  appeal.  We  should  no  longer  say  '  If 
variation  take  place  in  such  a  way/  or  '  //  such 
a  variation  were  possible ' ;  we  should,  on  the 
contrary,  be  able  to  say,  '  Since  variation  does, 
or  at  least  may,  take  place  in  such  a  way/ 
'  Since  such  and  such  a  variation  is  possible/ 
and  we  should  be  expected  to  quote  a  case,  or 
cases,  of  such  occurrence  as  an  observed  fact." 

In  the  most  general  terms  it  may  be  said  that 
one  of  the  greatest  steps  of  progress  in  evolution- 
lore  since  Darwin's  day  has  been  the  accumulation 


THE   RAW   MATERIALS    OF   EVOLUTION     101 

of  accurate  data  in  regard  to  the  variations  that 
do  actually  occur.  It  is  a  tedious  task,  but 
peremptorily  necessary,  and  already  it  is  having 
its  reward.  The  recording  and  statistical  registra- 
tion of  variations — such  as  we  find  in  the  pages 
of  the  journal  called  BiometriJca — is  rapidly  helping 
us  out  of  the  slough  of  vagueness,  in  which,  to 
the  physicist's  contempt,  biology  is  so  apt  to 
flounder.  Let  us  try  to  state  some  of  the  general 
impressions  that  we  get  from  the  post-Darwinian 
study  of  variation. 

(1)  Variations  more  Abundant  than  even 
Darwin  supposed. — "  Even  Darwin  himself,"  as 
Wallace  says,  "  did  not  realise  how  much  and 
how  universally  wild  species  vary";  but  one  of 
the  clear  results  of  much  patient  work  of  recent 
years  has  been  the  proof  that  variations  are  as 
marked  among  creatures  living  wild  in  nature 
as  they  are  among  those  under  man's  control. 
The  fountain  of  change  is  even  more  copious 
than  was  dreamed  of. 

In  commenting  on  the  "  fallacy  of  the  belief 
that  great  variation  is  much  rarer  in  wild  than 
in  domesticated  animals,"  Mr.  Bateson  notes 
that  "  if  we  examine  the  variation  in  the  vertebrae 
of  the  sloths,  in  the  teeth  of  the  anthropoid 
apes,  in  the  colour  of  the  dog-whelks  (Purpura 
lapillus),  etc.,  we  find  a  frequency  and  a  range  of 
variation  matched  only  by  the  most  variable  of 
domesticated  animals."  We  get  the  same  im- 
pression when  we  look  at  a  good  collection  of 
cuckoo's  eggs,  or  of  land-snails,  or  of  ruffs,  and 
so  on  through  a  long  list. 

It  is  difficult  to  realise  the  frequency  and  amount 
of  variations  until  one  begins  to  measure  and 


102       DARWINISM   AND    HUMAN    LIFE 

weigh.  In  1871  Mr.  J.  A.  Allen  measured  numerous 
individual  representatives  of  some  common  species 
of  American  birds,  and  found  that,  as  regards 
important  points,  e.g.  length  of  bill  and  length 
of  wing,  birds  of  the  same  sex  and  season,  caught 
at  the  same  place,  on  the  same  day,  showed 
numerous  variations,  often  large  in  amount.  "  The 
facts  of  the  case,"  Mr.  Allen  says,  "  show  that 
variation  of  from  15  to  20  per  cent,  in  general 
size,  and  an  equal  degree  of  variation  in  the  relative 
size  of  different  parts,  may  be  ordinarily  expected 
among  specimens  of  the  same  species  and  sex 
taken  at  the  same  locality,  while  in  some  cases 
the  variation  is  even  greater  than  this." 

(2)  Proportion  between  Frequency  and  Amount 
of  Variations. — Another  fact  has  been  made  clear 
in  regard  to  variations :  there  is  a  proportion 
between  the  frequency  of  a  particular  change 
and  the  amount  of  its  departure  from  the  mean 
of  the  character  in  question.  In  other  words, 
the  variations,  when  plotted  out,  show  what  is 
called  the  Curve  of  Frequency  of  Error.1  In 

1  Quetelet  (1846)  showed  that  variation  followed  the  law  of 
frequency  of  error,  the  mathematical  expression  of  which  was 
discovered  by  Gauss.  Sir  John  Herschel,  in  illustrating  this,  took 
the  case  of  a  rifleman  aiming  at  a  target.  "  It  was  pointed  out 
that,  irrespective  of  the  skill  of  the  rifleman,  the  shots,  after  a 
large  number  of  trials,  would  be  aggregated  most  thickly  about 
the  centre  of  the  target,  and  would  be  more  and  more  thinly  scat- 
tered the  farther  the  distance  became  from  the  centre  of  the  target. 
The  only  difTerence  between  the  targets  of  a  good  and  of  a  bad 
rifleman  is  that  in  the  former  case  the  total  area  which  contains 
all  the  shots  would  be  smaller  than  in  the  latter  case.  But  in 
each  case  the  centre  of  the  area  would  coincide  with  the  centre 
of  the  target,  and  the  distribution  of  shots  within  the  area  would 
be  similar.  The  explanation  of  this  result  rests  upon  the  cir- 
cumstance that,  each  time  the  rifleman  takes  aim,  a  number  of 
factors  come  into  operation,  tending  to  disturb  the  correctness 


THE   RAW   MATERIALS    OF   EVOLUTION    103 

measurements  of  2,600  men,  taken  at  random, 
Wallace  notes  that  there  is  1  of  4  ft.  8  in.  and 
1  of  6  ft.  8  in. ;  12  of  5  ft.  and  about  12  of  6  ft.  4  in. ; 
equal  numbers  at  equal  distances  from  the  mean 
of  5  ft.  8  in. 

This  tedious  work  of  registering  the  variations 
that  occur  may  lead  us  right  into  the  heart  of 
the  matter;  thus  the  asymmetry  or  skewness  of 
the  curve  may  show  us  at  a  glance  that  the  species 
is  moving  in  a  definite  direction  as  regards  the 
particular  character  measured,  or  the  formation 
of  a  double-humped  curve  may  vividly  bring 
home  the  fact  that  the  species  is  dividing  into 
two  sub-species.  Thus,  by  a  statistical  path,  we 
are  brought  face  to  face  with  the  most  vital  of 
all  facts — devolution  creatrice. 

(3)  Correlation  of  Variations. — Another  im- 
pression which  we  get  from  some  of  the  modern 
work  on  variation  is,  that  the  living  creature 

of  the  alignment  of  the  rifle.  But  as  these  factors  act  with  equal 
frequency  in  every  direction,  it  follows  that  the  point  of  thickest 
distribution  of  the  shots  will  still  remain  at  the  centre  of  the  target. 
Now,  variation  is  found  to  follow  precisely  the  same  law.  If  measure- 
ments of  some  character  are  taken  in  a  large  number  of  individuals, 
it  is  found  that  there  is  a  mean  measurement  in  the  neighbourhood 
of  which  the  individuals  are  most  thickly  clustered,  and  that  the 
further  the  distance  from  the  mean,  the  fewer  are  the  individuals 
represented.  The  analogy  goes  yet  farther :  for,  just  as  in  the 
case  of  the  good  and  bad  riflemen,  we  found  the  shots  to  be  in 
close  juxtaposition  or  more  widely  scattered,  so  in  the  case  of 
variation,  it  is  found  that  the  divergences  from  the  mean  are  in 
some  cases  far  more  accentuated  than  in  other  cases ;  that  is  to 
say,  the  degree  of  constancy  or  variation  in  different  organs  is 
very  different.  But  in  all  cases  the  variation  can  be  represented 
by  a  geometrical  curve,  the  ordinates  of  which  are  proportional 
to  the  terms  in  the  expansion  of  the  binomial  (a  +  6).  Occasionally 
the  individuals  are  found  to  cluster  round  two  or  more  points  of 
thickest  distribution,  and  it  is  then  inferred  that  they  belong  to 
two  or  more  different  races," — Edinburgh  Jiei'iew,  Jan.  1909, 


104       DARWINISM   AND    HUMAN   LIFE 

varies,  in  many  cases,  as  a  unity,  not  in  this 
corner  and  that — like  a  machine  that  is  perfected 
by  the  accumulation  of  little  patents, — but  through 
and  through  and  all  at  once.  As  Darwin  pointed 
out,  there  is  a  "  correlation  of  variations."  One 
change  brings  another  in  its  train,  and  the  one 
that  is  for  the  time  most  important  may  evolve 
another  much  more  important.  Thus  a  variation 
too  small  in  itself  to  be  of  value  may  be  carried 
over  the  dead  point  into  effectiveness  because  it 
is  physiologically  bound  up  with  another  variation. 

Another  aspect  of  the  same  idea  is  that  what 
seem  to  be  new  departures  in  widely  separated 
parts  of  the  animal  may  be  really  diverse  outcrops 
of  one  deep  physiological  change.  We  may  have 
thought  of  this  in  connection  with  some  disease 
that  we  have  watched :  it  has  very  different 
expressions  in  different  parts  of  the  body,  though 
it  is  due  to  a  single  slight  derangement  in  the 
normal  sequence  of  chemical  events.  We  may 
have  thought  of  the  same  idea  in  connection 
with  sex,  where  changes  apparently  confined 
to  minute  and  superficial  and  unconnected  parts 
may  be,  as  it  were,  the  correlated  outcrop  of 
one  deep  physiological  change.1  It  is  a  familiar 
fact  that  numerous  apparently  distant  and  un- 
connected changes  of  adolescence  are  all  funda- 
mentally one.  Similarly,  when  an  individual  plant 
or  animal  varies  as  a  whole,  when  compared  with 
its  parent,  this  means  that  the  potential  individual, 
the  germ-cell,  has  varied  as  a  unity. 

(4)  Brusque  Variations  more  Frequent  than 
was  formerly  supposed. — But  the  most  important 

1  "  The  Evolution  of  Sex,"  by  P.  Geddes  and  J.  Arthur  Thomson, 
"Contemporary  Science  Series  "  (1889).  Bevised  Edition  (1901). 


THE   RAW   MATERIALS    OF    EVOLUTION     105 

general  result  of  the  modern  study  of  variability 
is  the  evidence  that  changes  of  considerable 
amount  sometimes  occur  at  a  single  leap. 
These  brusque  changes  are  called  "discontinuous 
variations/'  and,  in  certain  cases,  "mutations." 
Lamarck  said,  "Nature  is  never  brusque,"  and 
we  usually  look  askance  at  reports  of  "  Jack-in- 
the-Box  "  phenomena  in  nature ;  but,  through  the 
solid  work  of  Bateson,  De  Vries,  and  others,  there 
is  more  reason  to-day  than  there  was  fifty  years 
ago  to  believe  that  organic  structure  may  pass 
with  seeming  abruptness  from  one  position  of 
organic  equilibrium  to  another. 

DISCONTINUOUS  VARIATIONS. — In  the  individual 
development  of  an  embryo  there  is  gradual  con- 
tinuous change  from  hour  to  hour,  from  day  to  day ; 
and  if  we  suppose  similar  changes  to  occur,  not  as 
normal  stages  in  the  development  of  one  creature, 
but  as  new  steps  of  progress  in  successive  genera- 
tions of  creatures,  we  have  the  individual  variations 
that  Darwin  most  believed  in  as  furnishing  the 
raw  materials  of  evolution.  But  in  many  a  develop- 
ment, such  as  that  of  a  starfish  or  a  butterfly, 
there  is  in  a  certain  sense  discontinuity  ;  there  is  a 
crisis,  when  the  developing  creature  recommences 
on  a  new  track  ;  and  this  sort  of  change  occurring, 
not  as  a  normal  event  in  individual  development, 
but  as  a  new  departure  in  racial  evolution,  would 
be  a  "  discontinuous  variation."  Using  Galton's 
simile,  we  can  picture  a  polyhedron  oscillating  or 
rocking  on  one  of  its  faces:  this  would  be  an 
"  individual  variation,"  or  fluctuation  ;  we  can  also 
picture  it  rolling  over  to  a  position  of  equilibrium 
on  another  face :  this  would  be  "  discontinuous 
variation/'  or  mutationr 


106       DARWINISM   AND   HUMAN   LIFE 

The  greatest  contribution  in  this  connection  is 
Bateson's  work  entitled,  "  Materials  for  the  Study 
of  Variation/'  which  showed  that  discontinuous 
variations  of  certain  kinds  are  not  uncommon. 
Abundant  evidence  is  given  of  "  the  existence  of 
sudden  and  discontinuous  variation  ;  the  existence, 
that  is  to  say,  of  new  forms  having  from  their  first 
beginning  more  or  less  of  the  kind  of  perfection 
that  we  associate  with  normality." 

MUTATIONS. — The  idea  that  the  Proteus  may 
leap  as  well  as  creep  is  prominent  in  the  work  of 
the  Dutch  botanist  De  Vries,  embodied  in  his 
"  Mutations-Theorie."  De  Vries  tells  the  story,  for 
instance,  of  a  stock  of  the  evening  primrose 
((Enothera  lamarckiana],  which  he  found  as  an 
escape  in  a  potato-field  near  Amsterdam.  It  was, 
as  it  were,  frolicking  in  its  freedom  ;  "  sporting,"  as 
we  say.  Almost  all  its  organs  were  varying,  as 
if  swayed  by  a  restless,  internal  tide.  It  showed 
minute  fluctuations  from  generation  to  generation  ; 
it  showed  extraordinary  freaks,  such  as  fasciation 
and,  pitcher-forming ;  it  showed  hesitancy  as  to 
how  long  it  meant  to  live,  for  while  most  were 
biennial,  many  were  annual,  and  a  few  were 

Lennial ;  best  of  all,  it  showed  what  seemed  like 

iw  species  in  the  making.  From  this  stock  De 
Vries  obtained,  in  a  short  time,  half  a  dozen  or  more 
distinct  varieties  or  elementary  species,  breeding 
true  generation  after  generation.  He  was  led  to 
the  important  conclusion  that  "  new  varieties  are 
produced  from  existing  forms  by  sudden  leaps." » 

1  It  is  unfortunate  that  nothing  certain  is  known  as  to  the  origin 
of  (Enothera  lamarckiana,  which  has  been  in  cultivation  for  a 
long  time.  It  is  possible  that  its  "  mutations  "  result  from  the 
impurity  of  the  stock,  As  Prof.  S,  J.  Holmes  says,  in  an  interesting 


THE   RAW   MATERIALS    OF   EVOLUTION    107 

The  first  part  of  the  Dutch  botanist's  great  work 
was  published  forty-three  years  after  "  The  Origin 
of  Species,"  and  there  are  many  who  regard  the 
Mutation  Theory  and  Mendelism  as  the  two 
greatest  steps  of  progress  that  have  been  made  in 
evolution-lore  since  1859.  Others,  such  as  Alfred 
Russel  Wallace,  the  Nestor  of  the  evolutionist  camp, 
are  very  far  from  sharing  this  view.  In  any  case 
we  must  try  to  understand  what  mutations  are  and 
what  their  significance  may  be. 

The  general  idea  is  that  novel  characters  may 
suddenly  appear,  as  it  were,  full-fledged,  with  con- 
siderable perfectness  from  the  moment  of  their 
emergence,  and  without  intergrades  linking  them  to 
the  parents.  Furthermore,  the  novel  character  of 
the  mutant,  if  we  may  use  the  word,  is  independently 
heritable  and  does  not  blend ;  it  can  be  grafted 
intactly  on  to  another  stock,  or  it  can  be  dropped 
out  as  such.  Again,  mutations  are  what  may  be 
called  qualitative,  as  contrasted  with  the  fluctua- 
tions which  are  quantitative.  Thus,  some  of  the 
new  evening  primroses  which  De  Vries  got  out 
of  his  changeful  stock  of  (Enothera  lamarckiana 
were  very  different  from  the  parent  type — some  had 
few  branches  instead  of  many,  some  had  small 
flowers  instead  of  large,  some  had  quite  different 
leaves,  and  so  on.  Mutations  have  been  recorded 
for  a  number  of  other  plants,  such  as  violets  and 
shepherd's  purse ;  but  the  inquiry  is  still  young. 

Among  animals  in  nature  we  know  as  yet  of  few- 
paper  on  "  The  Categories  of  Variation  "  (American  Naturalist  (1909), 
vol.  xliii.  p.  277) :  "  Should  it  turn  out  to  be  derived  from  a  mixture 
of  two  or  more  forms,  the  mutation  theory  would  be  deprived 
of  some  of  its  best  evidence ;  but  there  would  still  remain  a  con- 
siderable number  of  mutations  from  pure  ancestry," 


108       DARWINISM   AND    HUMAN   LIFE 

sudden  emergences  of  qualitatively  new  characters, 
but  several  cases  have  been  reported.  Thus  pink 
katydids  may  abruptly  appear  among  green  ones, 
and  short-winged  insects  in  a  long-winged  race, 
in  both  cases  without  intergrades.  Mutations  are 
also  described  among  freshwater  fishes  and  among 
medusae. 

When  we  turn,  however,  to  domesticated  animals, 
where  we  have  greater  opportunities  of  intimate 
observation,  the  case  for  mutation  becomes 
stronger.  There  are  sudden  negative  changes — 
the  entire  dropping  out  of  a  character — as  seen  in 
the  abrupt  appearance  of  hornless  cattle,  sheep,  and 
goats,  of  hairless  dogs  and  horses,  of  tailless  cats 
and  dogs.  There  are  also  sudden  positive  changes 
— the  acquisition  of  a  new  character — such  as  the 
appearance  of  extra  digits  in  poultry  and  pigs. 
Those  who  have  bred  birds  are  familiar  with  such 
sports,  which  are  often  striking.  There  is  evidence 
in  a  number  of  cases  that  stable  and  successful 
breeds  have  been  established,  not  by  the  slow 
increase  of  minute  fluctuations,  but  by  getting  a 
big  start  in  a  mutation.  In  many  cases,  although 
breeding  or  cultivation  has  grafted  the  novelty  on  to 
a  strong  stock  and  made  it  prepotent,  it  has  not 
greatly  increased  the  magnitude  of  the  quality 
which  the  original  sport  exhibited. 

DARWIN'S  POSITION  IN  REGARD  TO  MUTATIONS. 
— Though  Darwin  had  not  the  conception  of  unit 
characters — that  is  to  say,  independently  heritable 
characters  which  are  handed  on  intact  or  dropped 
out  altogether — in  its  modern  clear-cut  form,  he 
was  well  acquainted  with  mutations  in  domesticated 
animals  and  cultivated  plants,  and  he  dismissed 
most  of  them  as  not  important.  In  the  first  place, 


THE    RAW    MATERIALS    OF    EVOLUTION     109 

they  seemed  to  him  to  partake  too  much  of  the 
pathological.  But  we  must  not  hurriedly  dismiss 
mutations  like  that  of  fowls  with  webbed  feet  and 
no  tails  as  obviously  teratological,  for  most  of 
them  may  be  matched  in  nature.  If  there  were 
only  one  specimen  of  a  cross-bill,  for  instance, 
would  it  not  be  regarded  as  a  freak  which  could  not 
possibly  survive  in  nature  ?  In  the  second  place, 
reacting  as  he  was  against  a  catastrophic  view  of 
nature,  and  looking  at  things  (as  he  said)  through 
Lyell's  *  eyes,  Darwin  naturally  fought  shy  of 
big  sudden  changes.  Moreover,  as  he  said  to  Asa 
Gray  :  "  There  seems  to  me  in  almost  every  case 
too  much,  too  complex,  and  too  beautiful  adapta- 
tion in  every  structure  to  believe  in  its  sudden 
production."  Finally,  he  thought  that  a  full- 
fledged  new  character  appearing  suddenly  would 
be  swamped  by  intercrossing.2 

The  last  difficulty,  which  is  the  only  serious  one, 
has  been  removed,  for  it  is  characteristic  of  muta- 
tions that,  when  they  arrive,  they  come  to  stay, 
unless  they  be  eliminated  as  disadvantageous.  In 

1  It  was  characteristic  of  the  Lyellian,  or  Uniformitarian  school 
of  geologists  to  explain  large  results  on  the  principle  of  slow  suc- 
cessive increments,  accumulating  for  a  very  long  time. 

2  Let  us  hear  what  he  says  in  the  last  edition  of  "  The  Origin 
of  Species  "  : 

"  Mr.  Mivart  is  further  inclined  to  believe,  and  some  naturalists 
agree  with  him,  that  new  species  manifest  themselves  '  with  sudden- 
ness and  by  modifications  appearing  at  once.  .  .  .'  This  con- 
clusion, which  implies  great  breaks  or  discontinuity  in  the  series, 
appears  to  me  improbable  in  the  highest  degree  "  (p.  201). 

"  Although  very  many  species  have  almost  certainly  been 
produced  by  steps  not  greater  than  those  separating  fine  varieties, 
yet  it  may  be  maintained  that  some  have  been  developed  in  a 
different  and  abrupt  manner.  Such  an  admission,  however, 
ought  not  to  be  made  without  strong  evidence  being  assigned  " 
(p.  203). 


110       DARWINISM   AND   HUMAN   LIFE 

other  words,  a  new  unit  character  of  a  beetle  or 
of  a  shepherd's  purse — two  experimentally  tested 
instances — does  not  blend  when  its  possessor  is 
crossed  with  the  original  type.  It  is  not  swamped 
by  intercrossing,  but  reappears  in  its  integrity  in 
a  definite  proportion  of  the  succeeding  generations. 
Already  in  actual  practice  in  wheat-growing  it  is 
being  found  that  selected  single  ears  breed  true, 
and  that  no  further  selection  is  needed. 

The  attractiveness  of  the  mutation  theory  is  so 
great  that  we  must  be  particularly  cautious  in  our 
acceptance  of  it.  It  would  relieve  the  difficulties 
that  many  naturalists  have  in  believing  that  the 
apparent  big  lifts  and  qualitative  changes  which 
the  history  of  organic  life  implies  have  arisen  by 
the  natural  selection  of  minute  individual  fluctua- 
tions. It  would  make  more  intelligible  the  dis- 
continuity of  many  species,  if  we  found  reason  to 
believe  in  their  saltatory  origin.  It  need  hardly 
be  said  that  the  origin  of  the  mutation  would 
remain  a  mystery,  for  the  mutation  theory  is  not 
a  theory  of  mutations.  It  will  be  interesting  if 
evidence  accumulate  to  show  that  the  Proteus 
leaps  as  well  as  creeps,  if  future  generations  look 
back  to  Darwin  as  the  naturalist  who  saw  nature 
moving  by  small  steps,  while  Dr.  Vries  caught  a 
glimpse  of  her  dancing  ! 

ORIGIN  OF  VARIATIONS. — In  regard  to  the  difficult 
question  of  the  origin  of  variations,  we  must  not  be 
impatient  to  answer  until  our  knowledge  of  their 
nature  has  greatly  increased.  We  must  still  confess, 
with  Darwin :  "  Our  ignorance  of  the  laws  of  varia- 
tion is  profound.  Not  in  one  case  out  of  a  hundred 
can  we  pretend  to  assign  any  reason  why  this  or 
that  part  has  varied."  And  again  he  said : 


THE   RAW   MATERIALS    OF    EVOLUTION     111 

"  If,  as  I  must  think,  external  characters  produce 
little  direct  effect,  what  the  devil  determines  each 
particular  variation  ?  " 

Having  made  this  confession  of  ignorance,  we 
venture  to  discuss  the  possibilities  of  answer  to  a 
question  which  can  never  be  far  from  any  thought- 
ful mind. 

There  are  variations  and  variations.  There  are 
variations  that  mean  nothing  more  than  an  aug- 
mentation or  diminution  of  an  already  existing 
quality.  The  hair  may  be  very  long  or  the  tail 
very  short.  Or  a  variation  may  mean  that  a 
character  present  in  parents  and  ancestry  is  absent 
from  the  offspring :  the  entail  has  been  broken. 
An  albino  expresses  such  a  variation,  or  a  hornless 
calf,  or  a  tailless  kitten.  Or,  again,  a  variation 
may  be  interpretable  as  a  novel  arrangement  of 
characters  or  qualities  which  were  present  in  the 
ancestry.  A  piebald  pony  may  serve  as  a  diagram. 

Now,  in  regard  to  variations  of  this  sort — 
which  may  be  described  as  permutations  and 
combinations  of  the  already  existing  unit  char- 
acters— the  modern  knowledge  of  the  conditions 
of  heredity  has  made  it  plain  that  there  are  many 
opportunities  for  their  occurrence  before,  during, 
and  after  fertilisation.  We  know  that  each  germ- 
cell  contains  a  definite  number  of  stainable  bodies, 
or  chromosomes,  which  appear  to  be  the  bearers 
of  the  heritable  qualities.  We  may  compare  these 
to  a  microscopic  pack  of  cards,  and  we  may  say 
th  there  is  an  extraordinarily  elaborate  shuffling 
beiore  development  begins.  Half  of  the  pack  is 
ejected  from  the  egg-cell  in  what  is  known  as  a 
"  polar  body,"  and  the  number  is  raised  to  the 
normal  again  (constant  throughout  the  body  of  the 


112       DARWINISM   AND   HUMAN   LIFE 

organism)  by  the  entrance  of  the  fertilising  sperma- 
tozoon whose  chromosomes  have  also  been  reduced 
by  a  half.  In  fertilisation,  at  the  beginning  of 
each  new  life,  there  is  an  intricacy  of  combination 
that  may  be  likened  to  the  making  of  a  living 
mosaic  out  of  parental  and  ancestral  contributions. 
It  may  also  be  that  in  the  making  of  the  germ- 
cells  there  is  a  segregation  of  antithetic  qualities, 
so  that  two  different  kinds  of  germ-cells  result, 
corresponding  to  the  two  sharply  contrasted 
parents.  It  may  also  be,  as  Weismann  supposes, 
that  there  is  a  struggle  between  rival  unit-char- 
acters in  the  penetralia  of  the  germ-cells.  In 
any  case,  there  is  abundant  opportunity  for  new 
permutations  and  combinations.  There  are  many 
factors  which  may  give  the  vital  kaleidoscope  a 
twist. 

There  is,  however,  another  kind  of  variation, 
when  novel  features  appear,  which  are  qualitative 
rather  than  quantitative,  substantive  rather  than 
architectural,  in  kind  rather  than  in  degree,  and 
more  than  mere  rearrangements  of  previously 
expressed  unit  characters.  What  can  be  said  as 
to  their  origin  ? 

Weismann  and  others  have  suggested  that 
the  stimulus  to  germinal  variations  comes  from 
the  oscillations  and  changes  in  the  immediate 
surroundings  of  the  germ-cells.  They  get  their  food- 
supply  from  the  body,  and  that  food-supply  is 
liable  to  be  somewhat  variable.  It  may  contain 
a  poison,  for  instance,  which  seriously  shakes 
the  architecture  of  the  germ-plasm  at  the  very 
start;  but  it  may  also  contain  some  stimulus, 
which  provokes  the  living  germ  to  a  new  de- 
parture. 


THE   RAW   MATERIALS    OF   EVOLUTION    113 

Another  suggestion,  which  has  some  interesting 
experimental  evidence  behind  it,  is  that  important 
changes  in  the  environment — changes  in  chemical 
composition,  heat,  light,  and  electrical  conditions, 
and  so  on — may  saturate  deeply  through  the 
body  and  stimulate  the  germ-cell  to  change.  We 
shall  return  to  this  suggestion  later  on. 

GERMINAL  SELECTION. — In  his  theory  of  "  ger- 
minal selection"  Weismann  has  elaborated  an 
interesting  speculation  in  regard  to  the  roots  of 
variation.  With  his  characteristic  way  of  following 
an  idea  as  far  as  it  will  lead  him,  he  has  extended 
the  concepts  of  struggle  and  selection  to  the 
primary  constituents  (or  determinants)  within 
the  germ-cell.  In  consequence  of  unequal  nutrition 
these  primary  constituents  are  always  varying.  If 
one  of  them,  corresponding,  let  us  say,  to  a  sense- 
cell,  receives  for  a  considerable  time  more  abundant 
food  than  before,  it  will  grow  in  proportion,  and 
if  the  germ-cell  develops  into  an  organism  the 
sensory  cell  may  be  twice  as  strong  as  it  was  in 
the  parent. 

But  the  strengthened  determinant  may  begin 
actively  to  nourish  itself  more  abundantly — 
attracting  the  food  to  itself,  and  in  some  measure 
withdrawing  it  from  its  fellow-determinants.  In 
this  way  "  it  may  get  into  a  permanent  upward 
movement,  and  attain  a  degree  of  strength  from 
which  there  is  no  falling  back." 

In  a  similar  manner  a  downward  variation  of 
a  determinant  may  be  started  by  diminished 
nutrition,  and  the  weakened  determinant  will 
have  less  affinity  for  attracting  nutriment  because 
of  its  diminished  strength.  "  If  a  certain  critical 
stage  of  downward  progress  be  passed,  even 

8 


114       DARWINISM   AND    HUMAN    LIFE 

favourable  conditions  of  food-supply  will  no 
longer  suffice  permanently  to  change  the  direction 
of  the  variation/' 

If,  in  such  a  case,  the  determinant  be  that  of 
a  useful  structure,  then  the  ordinary  process  of 
natural  selection  will  remove  the  individual ;  but 
if  the  weakened  determinant  be  that  of  a  useless 
organ  it  will  continue  getting  weaker  generation 
after  generation. 

"  In  most  cases  the  fluctuations  will  counteract 
one  another,  because  the  passive  streams  of 
nutriment  soon  change;  but  in  many  cases  the 
limit  from  which  a  return  is  possible  will  be  passed, 
and  then  the  determinants  concerned  will  continue 
to  vary  in  the  same  direction  till  they  attain 
positive  or  negative  selection-value.  At  this  stage 
personal  selection  intervenes  and  sets  aside  the 
variation  if  it  is  disadvantageous,  or  favours — 
that  is  to  say,  preserves — it  if  it  is  advantageous. 
But  the  determinant  of  a  useless  organ  is  un- 
influenced by  personal  selection,  and,  as  experience 
shows,  it  sinks  downwards ;  that  is,  the  organ 
that  corresponds  to  it  degenerates  very  slowly 
but  uninterruptedly  till,  after  what  must  obviously 
be  an  immense  stretch  of  time,  it  disappears  from 
the  germ-plasm  altogether/'  Thus  "  germinal 
selection  supplies  the  stones  out  of  which  personal 
selection  builds  her  temples  and  palaces :  adapta- 
tions." 1 

The  theory  is,  of  course,  entirely  hypothetical, 
dealing  as  it  does  with  the  invisible,  but  it  enables 
us  to  formulate  a  large  number  of  facts. 

VARIATIONAL  STIMULI. — Some  of  the  most  in- 
teresting and  striking  work  of  the  last  dozen  years 

1  "  The  Evolution  Theory,"  by  Weismann  (1904),  voL  ii. 


THE   RAW   MATERIALS    OF   EVOLUTION    115 

must  be  referred  to  in  connection  with  the  origin 
of  variations.  It  has  been  shown  experimentally 
that  chemical  substances  in  the  food  of  the  mother 
may  be  carried  on  into  the  offspring.  Thus,  when 
the  dye  known  as  Sudan  is  mixed  with  the 
food  of  hens,  it  appears  in  the  yolk  of  the  egg 
and  eventually  in  the  fatty  tissue  of  the  chick. 
Perhaps  this  sort  of  thing  is  commoner  than  is 
usually  supposed.  By  changing  the  temperature 
and  the  food  of  the  caterpillars  of  Vanessa  and 
Arctia,  Standfuss  and  Fischer  were  able  to  induce, 
in  the  next  generation,  aberrant  characters,  which 
remained  distinct  when  crossed  with  the  parent 
form. 

More  striking,  however,  are  the  experiments 
carried  on  for  twelve  years  by  Professor  Tower 
on  beetles  of  the  genus  Leptinotarsa,  which  he 
subjected  to  unusual  conditions  of  temperature 
and  moisture  when  the  male  or  female  reproductive 
organs  were  at  a  fixed  point  in  their  development. 
The  result  was  to  induce  in  the  offspring  striking 
changes,  not  only  in  colour  and  markings,  but 
also  in  some  details  of  structure.  Sometimes  all 
the  germ-cells  seemed  to  be  affected,  sometimes 
only  a  fraction  of  them  ;  sometimes  various  changes 
resulted  from  the  same  treatment ;  some  of  the 
changes  were  brusque,  others  showed  intergrades 
with  the  parental  conditions ;  sometimes  the 
change  did  not  occur  until  after  the  lapse  of 
several  generations  in  the  unusual  environment ; 
there  was  no  reversion  to  the  parental  condition. 
Of  course  Tower  could  not  get  at  the  reproductive 
organs  except  through  the  body,  but  it  should 
be  noted  that  the  body  of  the  parent  was  not 
changed,  and  it  was  only  at  particular  stages 


116       DARWINISM   AND   HUMAN   LIFE 

that  the  influence  was  operative.  Here,  then,  we 
have  definite  evidence  of  germinal  variation 
evoked  by  environmental  stimulus. 

Very  interesting,  also,  are  the  experiments  of  Dr. 

C.  S.  Gager,  who  exposed  the  egg-cells  and  pollen- 
cells  of  Onagra  biennis  to  Radium  rays,  and  found 
that  plants  grown  from  the  seeds  produced  under 
this  influence  were  very  different  from  the  parents, 
and  that  the  change  persisted  to  the  second  genera- 
tion at  least.    Here,  again,  there  is  proof  of  heritable 
variation  induced  by  environmental  stimulus. 

Shortly  before  his  death  Darwin  began  to 
experiment  on  the  possibility  of  producing  galls 
artificially.  "  He  imagined  to  himself  wonder- 
ful galls  caused  to  appear  on  the  ovaries  of 
plants,  and  by  these  means  he  thought  it  possible 
that  the  seed  might  be  influenced,  and  thus 
new  varieties  arise."1  What  Darwin  just  began 
has  been  carried  out  with  great  skill  by  Prof. 

D.  T.    MacDougal.     "  Among    other    operations, 
solutions  of  sugar,  calcium,  potassium,  and  zinc 
were  injected  by  the  use  of  hypodermic  syringes 
into  the  developing  ovaries  of  Raimannia,  one  of 
the  evening  primroses,   early  in   1905,   with  the 
result  that,  out  of  several  hundreds  of  seeds  borne 
by  the  treated  ovaries,  sixteen  individuals  were 
found   to   be   notably  atypic,  among  other  char- 
acters lacking  the  trichomes  which    are   so  con- 
spicuous with  the  parental  form.   These  reproduced 
themselves  in   the  second  and  third  generations, 
coming  true  to  the  newly-assumed  characters/'2 
Similar   experiments   were   made   with   (Enothera 

i  "Life  and  Letters  of  Charles  Darwin,"  vol.  ii.  p.  517. 
1  "  The   Direct  Influence   of   Environment,"    by   D.   T.  Mac- 
Dougal, in  "  Fifty  Years  of  Darwinism  "  (1909). 


THE   KAW   MATERIALS    OF    EVOLUTION     117 

biennis  and  Penstemon  wrightii,  and  we  have 
decisive  evidence  that  environmental  stimulus 
acting  directly  on  the  germ-cells  may  induce 
striking  variations.  This  is  a  very  important 
result,  for  it  is  evident  that  the  germ-cells  of 
animals  may  in  a  similar  way  be  naturally  stimu- 
lated to  vary  by  chemical  changes  in  the  vascular 
fluids.  With  the  flowers,  as  with  the  beetles,  there 
were  not  only  losses  and  augmentations  of  what 
was  previously  present,  but  there  were  distinct 
novelties  which  maintained  their  distinctness  when 
crossed  with  the  parental  strains. 

After  we  have  worked  for  years  along  the  lines 
of  these  various  suggestions  that  have  been  offered 
as  to  the  causes  of  variations,  we  shall  be  better 
able  to  say  how  far  they  account  for  what  we  believe 
has  occurred  in  the  past,  and  for  what  we  know 
to  occur  at  present.  Perhaps  they  will  prove 
insufficient,  and  evolutionists  will  be  forced  to 
recognise  that  variability  is,  like  growth,  a  primary 
quality  of  living  things,  and  that  "  breeding 
true "  has  arisen  secondarily  as  a  restriction. 
The  relation  of  genetic  continuity  between  succes- 
sive generations  is  an  economical  arrangement 
which  secures  relative  constancy  amid  continual 
flux,  but  in  spite  of  this  the  Proteus  continually 
asserts  itself.  Its  essence  is  creative  power.  It 
lives  because  it  changes,  it  changes  because  it 
lives.  From  generation  to  generation  there  is  a 
continuous  lineage  of  germ-cells;  but  just  as  we 
see  a  youth  growing  and  changing,  taking  time 
into  himself  and  making  himself,  in  some  ways, 
new  by  his  experience,  so  it  may  be  that  there  is  a 
power  of  growing  and  varying  inherent  in  the  germ- 
cells — as  also  in  the  unicellular  organisms  in  the 


118       DARWINISM   AND   HUMAN   LIFE 

waters — which  requires  only  time  and  experience 
to  produce  what  is  new. 

MODIFICATIONS,  OR  ACQUIRED  CHARACTERS. — 
We  must  now  ask  a  very  important  question.  Are 
there  no  other  raw  materials  of  evolution  besides 
those  inborn  changes  which  we  call  variations  and 
mutations,  which  we  trace  back  to  more  or  less 
mysterious  processes  occurring  in  the  germinal 
material  ?  It  is  well  known  that  our  bodies  suffer 
change  according  to  what  we  do  or  do  not  do,  and 
according  to  climate  and  food,  and  so  forth.  Does 
this  sort  of  change  not  furnish  part  of  the  raw 
material  of  evolution  ? 

Among  the  observed  differences  which  mark 
man  from  man,  or  trout  from  trout,  or  buttercup 
from  buttercup,  there  are  many  to  which  we  can- 
not apply  the  word  "variation."  For,  apart 
from  constitutional  or  inborn  changes,  there  are 
differences  which  are  impressed  upon  the  body 
in  the  course  of  life  by  influences  from  without, 
such  as  sun-burning  in  man  or  colour  in  trout ;  or 
by  use  and  disuse,  such  as  callosities  on  the  fingers. 
These  do  indeed  presuppose  a  constitution  capable 
of  being  changed,  but  we  can  relate  each  to  some 
definite  influence,  either  of  function  or  of  environ- 
ment, which  has  brought  about  a  structural  change 
transcending  the  limits  of  organic  elasticity.  We 
call  these  modifications,  and  though  they  may  be 
of  much  importance  to  the  individuals  possessing 
them,  they  are  not  known  to  be  of  any  direct 
importance  in  the  evolution  of  the  race,  for  the 
simple  reason  that  there  is  no  convincing  evi- 
dence that  they  can  be  transmitted.  Here  the 
Lamarckians  entirely  dissent ;  but  they  have  still 
to  prove  their  case. 


THE    RAW   MATERIALS    OF   EVOLUTION    119 

After  much  discussion  most  naturalists  have 
come  back  to  the  position  of  Kant,  that  life  does 
not  run  on  a  compound  interest  principle  of  adding 
to  the  child's  inheritance  the  individual  acquisi- 
tions (somatogenic  or  exogenous  modifications) 
of  the  parents.  As  a  matter  of  fact,  we  do  not 
know  of  any  clear  case  of  individual  modifications 
due  to  surroundings,  education,  work,  or  sloth, 
being  transmitted  in  any  degree  to  offspring.  That 
the  parents'  mode  of  life  influences  the  children 
yet  unborn  is  obvious ;  but  the  point  is,  whether  the 
influence  produces  a  corresponding  or  representa- 
tive effect. 

INDIRECT  IMPORTANCE  OP  MODIFICATIONS. — 
Those  who  find  no  warrant  for  accepting  the 
Lamarckian  postulate  of  the  transmissibility  of 
modifications,  do  not  thereby  assert  that  modifica- 
tions are  of  no  importance.  Many  living  creatures 
are  exceedingly  plastic,  and  their  modifiability 
sometimes  saves  them  where  their  variability  is 
at  fault.  This  idea  has  been  elaborated  independ- 
ently by  Profs.  Mark  Baldwin,  Lloyd  Morgan, 
and  H.  F.  Osborn,  and  we  venture  to  quote 
Lloyd  Morgan's  terse  summary : 

(1)  Variations  (V)  occur,  some  of  which  are  in 
the  dkection  of  increased  adaptation  (  +  ),  others 
in  the  direction  of  decreased  adaptation  (-). 
(2)  Acquired  modifications  (M)  also  occur.  Some 
of  these  are  in  the  direction  of  increased  accom- 
modation to  circumstances  ( + ),  while  others  are  in 
the  direction  of  diminished  accommodation  (  — ). 
Four  major  combinations  are — 

(a)  +  V  with  +  M.    (c)  -  V  with  +  M. 

(b)  +  V  with  -  M.    (d)  -  V  with  -  M. 


120       DARWINISM   AND    HUMAN    LIFE 

Of  these  (d)  must  inevitably  be  eliminated  while 
(a)  are  selected.  The  predominant  survival  of 
(a)  entails  the  survival  of  the  adaptive  variations 
which  are  inherited.  The  contributory  acquisi- 
tions +  M  are  not  inherited ;  but  they  are  none 
the  less  factors  in  determining  the  survival  of  the 
coincident  variations."  Lamarckians  believe  that 
useful  modifications  are  in  some  degree  sometimes 
transmitted.  On  the  view  just  sketched  the  modi- 
fications are  the  screens  or  nurses  of  coincident 
variations  in  the  same  direction. 

We  can  imagine  conditions  where  swarthiness 
was  a  character  of  life-saving  value,  where  the 
possessors  of  inborn  variations  in  the  direction  of 
swarthiness  were  favoured,  where  those  who  varied 
in  the  direction  of  increased  blondeness  were 
handicapped.  It  is  readily  intelligible  that  those 
who  could  acquire  swarthiness  as  an  individual 
somatic  modification  would  also  be  favoured,  and 
that  the  acquired  swarthiness  might  act  as  a  life- 
saving  screen  until  constitutional  and  heritable 
swarthiness  had  time  to  establish  itself. 

Furthermore,  although  modifications  may  not 
be  entailed,  they  may  have  occasionally  important 
indirect  influences  on  the  offspring.  A  starved 
mother  may  have  a  weakly  child. 

MODIFICATION-SPECIES. — In  the  case  of  animals 
and  plants  which  we  do  not  know  except  in 
particular  surroundings,  it  is  quite  possible  that 
characters  which  we  credit  to  inherited  nature 
may  be  impressed  on  every  successive  generation 
by  nurture.  Especially  among  the  more  vegeta- 
tive forms  of  life  we  find  indications,  which  experi- 
ment will  some  day  test,  that  there  are  what  may 
J>e  called  "  modification-species/'  which  differ  from 


THE   RAW   MATERIALS    OF   EVOLUTION     121 

nearly  related  species  only  because  the  conditions 
of  their  life  are  different. 

INDIVIDUAL  PLASTICITY. — At  all  events,  there 
is  great  interest  in  individual  plasticity,  in  what 
can  be  effected  by  changes  in  nurture.  We  must 
picture  the  living  creature  as  continually  running 
the  gauntlet  of  the  mechanical,  chemical,  physical, 
and  even  animate  influences  that  make  uj  its 
environment.  It  passes  over  a  series  of  anvils, 
on  each  of  which  the  hammers  ring  a  different 
tune.  Let  us  take  a  few  illustrations  from  among 
the  many. 

If  the  alkalinity  of  the  sea-water  be  slightly 
altered,  the  egg  of  a  sea-urchin  allows  itself  to  be 
fertilised  by  the  sperm  of  a  starfish,  or  of  a  crinoid, 
or  of  a  mollusc  (!),  producing  larvae  which  all  take 
after  the  mother. 

If  the  chemical  and  physical  state  of  the  sea- 
water  be  slightly  disturbed,  artificial  partheno- 
genesis can  be  induced  in  starfish  and  sea-urchin, 
in  worm  and  mollusc. 

Sometimes  the  result  of  a  slight  chemical  change 
is  very  perplexing,  and  there  are  many  experiments 
at  which  we  look  with  bated  breath.  Quaint 
abnormal  larvse  of  sea-urchin  and  frog  are  obtained 
by  adding  a  little  lithium  to  the  water,  and  the 
addition  of  a  little  magnesium  to  the  sea-water 
containing  embryos  of  the  fish  Fundulus  hetero- 
clitus  induces  in  a  large  number  of  these  the  de- 
velopment of  a  single  Cyclopean  eye  in  place  of 
the  normal  two  eyes.1 

A  small  Crustacean  called  Gammarus,  very 
common  in  fresh  water,  has  the  habit  of  avoiding 

1  Charles  R.  Stockard,  in  Journal  of  Experimental  Zoology, 
February  1909. 


122       DARWINISM   AND    HUMAN   LIFE 

the  light,  but  add  a  little  acid  so  that  the  solution 
is  no  stronger  than  yoootn  °*  one  Per  cent.,  and 
Gammarus  swims  towards  the  light. 

Remove  one  or  two  of  the  metals  from  sea- 
water,  keeping  up  the  alkalinity,  and  the  sea- 
urchin  egg  develops  into  twins.  Raising  the 
temperature  a  little  often  has  the  same  result. 

Cold  slows  growth  and  development,  yet  the 
population  of  floating  and  drifting  animals  is 
denser  in  the  Arctic  waters  than  in  the  Tropics — 
a  curious  fact  which  Prof.  Loeb  explains  by  showing 
that  lowering  the  temperature  greatly  increases 
the  duration  of  life.  There  are  more  generations 
living  at  the  same  time.  Lowering  the  temperature 
of  the  caterpillar  box  may  be  followed  by  curious 
aberrations  of  colour  in  the  moths  and  butterflies, 
especially  in  the  direction  of  melanism  (Standfuss, 
Fischer,  and  others).  Prof.  Poulton  showed  that 
the  caterpillars  of  the  small  tortoise-shell,  for 
instance,  are  for  a  short  time  so  sensitive  that 
those  in  a  white  or  gilded  box  have  light  or 
golden  pupse,  while  those  from  the  dark  box  have 
dark  pupse. 

The  influence  of  diet  alone  might  form  the  subject 
of  a  course  of  lectures.  Take  the  simple  but  very 
suggestive  fact  reported  by  Marchal  that  a  scale- 
insect,  Lecanium  corni,  becomes  L.  robiniarum  when 
reared  on  Robinia  pseudoacacia  instead  of  on  its 
own  normal  food-plant,  though  the  reverse  ex- 
periment does  not  succeed.  Or  consider  one  of 
the  most  interesting  of  recent  researches.  Mr. 
C.  W.  Beebe l  caused  the  scarlet  tanager  (Piranga 
erythromelas)  and  the  bobolink  (Dolichonyx  oryzi- 
vorus)  to  keep  their  breeding  plumage  through. 

i  American  Naturalist  (1908),  voL  xlii.  p.  34. 


THE   RAW   MATERIALS    OF    EVOLUTION     123 

the  year  by  giving  them  fattening  food  and  keeping 
them  without  much  exercise  in  dim  light.  Gradual 
return  to  the  light  and  the  addition  of  mealworms 
to  the  menu  brought  back  the  spring  song,  even 
in  mid-winter.  After  a  year,  and  at  the  beginning 
of  the  normal  breeding  season,  individual  tanagers 
and  bobolinks  were  gradually  brought  under  normal 
conditions  and  activities,  and  in  every  case  they 
moulted  from  nuptial  plumage  to  nuptial  plumage, 
the  dull  colours  of  the  winter  season  having  been 
skipped.  The  inherited  constitution  determines 
what  is  possible,  but  there  is  evidently  a  large 
range  of  plasticity.  We  do  not  know  that  modifica- 
tions are  entailed,  but  we  must  attach  all  the  more 
importance  to  the  influence  of  the  environment  in 
bringing  about  individual  adjustment,  in  stimu- 
lating variation,  and  in  punctuating  developmental 
processes. 

KELATION  TO  HUMAN  LIFE.— What  has  all  this 
discussion  regarding  fluctuations  and  variations 
and  mutations  and  modifications  to  do  with 
human  life  ?  It  would  be  easier  to  answer  this 
question  if  we  knew  more  about  these  changes, 
but  some  practical  considerations  are  obvious. 

To  begin  with,  man  probably  arose  by  a  mutation ; 
that  is  to  say,  by  a  discontinuous  variation  of 
considerable  magnitude.  Every  one  who  has  known 
a  genius  has  in  this  happy  experience  some  idea  of 
what  is  meant  by  a  mutation,  though  the  com- 
parison breaks  down  inasmuch  as  the  quality  of 
genius  is  rarely  heritable.  It  is  not  merely  that 
the  genius  has  more  brains ;  he  has  a  new  pattern 
of  brains,  and  a  large  mutation  is  a  new  constitu- 
tional pattern.  It  is  likely  that  man  had  his 
starting-point  as  a  prepotent  anthropoid  genius. 


124       DARWINISM   AND    HUMAN    LIFE 

Man's  origin  is  hidden,  and,  whatever  our  ancestry 
was,  we  cannot  change  it ;  man's  future  is  also 
hidden,  but  it  will  be,  in  some  measure,  of  our 
making.  Now,  it  is  evident  that  some  variations 
are  undesirable :  they  make  their  possessor  miser- 
able, and  his  neighbours  hardly  less  miserable.  We. 
admit  that  there  is  an  "  optimism  of  pathology  "  ; 
unpromising  buds  may  burst  into  flowers  as  fair  as 
they  are  unexpected,  weaklings  bend  Titans  to  their 
will,  cripples  make  the  world  go  round,  and  those  of 
marred  visage  teach  us  what  beauty  really  is ;  but, 
with  all  the  breadth  of  view  that  biology  will  allow, 
there  are  some  variations  on  which  the  verdict  of 
history  is  that  they  make  for  retrogression.  Every 
one  wishes  these  variations  to  die  out. 

There  are  other  variations  that  are  unmistakably 
desirable — in  the  direction  of  fine  physique, 
artistic  skill,  keen  mental  ability,  originality, 
socialised  disposition,  and  strength  of  character. 
Every  one  wishes  these  variations  to  be  widely 
distributed. 

Inquiry  into  the  history  of  good  animal  stocks 
shows  that  steady  progress  has  always  rewarded 
the  mating  of  nearly  related  forms,  while  the 
blending  of  distant  and  incompatible  types  seems 
often  to  lead  to  reversionary  mongrels.  Here  we 
have  a  warning  to  the  thoughtless  experimenter 
with  his  own  stock. 

One  of  the  characteristics  that  should  dis- 
tinguish the  biologist  is  an  expectancy,  an  open- 
mindedness,  a  tolerance,  even  a  reverence,  with 
respect  to  variations ;  for  these  new  departures 
on  the  part  of  the  ever-changing  organism  are  the 
raw  materials  of  progress,  and  should  be  sedulously 
guarded.  Individuality  is  often  born,  often 


THE    RAW   MATERIALS    OF    EVOLUTION     125 

smothered,  rarely  made.  A  man  with  an  idio- 
syncrasy, who  is  snubbed  as  an  impossible  person, 
may  be  a  Moses  who  might  have  led  us  out 
of  bondage  !  Captain  Fitzroy  nearly  refused  to 
take  Darwin  on  the  Beagle  voyage  because  of 
his  nose  ! 

For  various  reasons  biologists  take  a  strong 
interest  in  the  play  of  animals  and  of  children. 
Play  is  no  mere  safety-valve  for  overflowing 
animal  spirits :  it  is  a  rehearsal,  without  responsi- 
bilities, of  some  of  the  essential  activities  of  adult 
life.  But  it  is  more :  it  affords  what  the  Germans 
call  Abdnderungspiclraum — playground  for  varia- 
tions. The  playing  organisms  are  the  most 
educable. 

The  distinction  between  variations  and  modifica- 
tions seems  sometimes  academic  and  tiresome,  but 
if  we  understand  it  we  see  it  as  one  of  the  most 
practical  of  questions.  Do  the  innate  changes 
in  the  natural  inheritance  furnish  the  whole  raw 
material  of  progress,  or  do  the  changes  in  the  body 
due  to  peculiarities  of  nurture  furnish  some  ?  At 
present  the  scientific  answer  seems  to  be,  that  the 
raw  material  of  organic  evolution  is  due  to  varia- 
tions, and  in  no  direct  way  due  to  modifications. 
How  closely  this  touches  human  life  !  There  is 
social  evolution  as  well  as  organic  evolution,  and 
social  evolution  has  provided  an  apparatus  whereby 
the  gains  of  experience  may  swell  the  legacy  of 
successive  generations,  although  they  do  not,  from 
the  nature  of  the  case,  become  part  of  the  germinal 
inheritance. 

As  Lloyd  Morgan  *  well  says  :  "  The  history  of 

1  "Mental  Factors  in  Evolution,"  in  "Darwinism  and  Modern 
Science"  (1909),  p.  445. 


126       DARWINISM   AND    HUMAN   LIFE 

human  progress  has  been  mainly  the  history  of 
man's  higher  educability,  the  products  of  which 
he  has  projected  on  to  his  environment.  This 
educability  remains,  on  the  average,  what  it  was 
a  dozen  generations  ago ;  but  the  thought- woven 
tapestry  of  his  surroundings  is  refashioned  and 
improved  by  each  succeeding  generation." 

"  Few  men  have  in  greater  measure  enriched  the 
thought-environment  with  which  it  is  the  aim  of 
education  to  bring  educable  human  beings  into 
vital  contact  than  has  Charles  Darwin." 


CHAPTER  V 
FACTS  OF  INHERITANCE 


127 


CHAPTER   V 

FACTS   OF  INHERITANCE 

Progress  during  the  Darwinian  Era — Demonstration  of  Heritable 
Qualities — Heredity,  a  Term  for  the  Genetic  Relation  between 
Successive  Generations — Appreciation  of  Distinction  between 
Nature  and  Nurture — The  Idea  of  the  Continuity  of  Genera- 
tions— Critical  Attitude  in  Regard  to  Various  Conclusions — 
Mendelism — Methods  of  Studying  Heredity — Microscopical 
Study  of  the  Germ-cells — Statistical  Study  :  Filial  Regression 
— Galton's  Law  of  Ancestral  Inheritance — Experimental  Study 
— Pairing  of  Similar  Pure-bred  Forms — Blending — Particulate 
Inheritance — Exclusive  Inheritance — Reversion — New  Depar- 
tures— Mendelian  Inheritance — Unit  Characters — The  Case 
of  Andalusian  Fowls — Waltzing  Mice — Occurrence  of  Mendelian 
Inheritance — Practical  Importance  of  Mendelism — Much 
Progress  but  Great  Uncertainty — Transmission  of  Acquired 
Characters — Disease — Facts  and  Possibilities — A  Striking  Case 
— Logical  Position  of  the  Question — Cases  where  the  Theory 
of  Modification-inheritance  is  Inapplicable — Importance  of 
Environment  and  Function  Remains — Selection  and  Stimulus 
— Indirect  Importance  of  Modifications — Practical  Import  of 
the  Question  as  to  the  Transmission  of  Acquired  Characters — 
Inheritance  of  Moral  Character — Three  General  Conclusions. 

EVEN  in  ancient  times  men  pondered  over  the 
resemblances  and  differences  between  children  and 
their  parents,  and  wondered  as  to  the  nature  of 
the  bond  which  links  generation  to  generation; 
but,  although  a  recognition  of  these  problems  is 
old,  the  precise  study  of  them  is  altogether  modern, 
and  may  almost  be  called  Darwinian.  For  it  was 
largely  through  Darwin's  influence  that  the  scientific 
study  of  heredity  began.  "  Before  and  after 
Darwin/'  Professor  Osborn  says,  "  will  always  be 

129  9 


130       DARWINISM   AND    HUMAN    LIFE 

the  ante  et  post  urbem  conditam  of  biological  history  " ; 
so  it  may  be  useful  to  inquire  into  the  advances 
that  have  been  made  in  the  study  of  heredity  since 
the  beginning  of  Darwin's  day.1 

PROGRESS  DURING  THE  DARWINIAN  ERA.  (1) 
Demonstration  of  Heritable  Qualities. — Before  1859 
much  attention  was  given  to  the  demonstration 
of  the  general  fact  of  inheritance.  In  a  large 
treatise  like  that  of  Prosper  Lucas  (1847)  many 
hundreds  of  pages  are  devoted  to  proving,  what  we 
now  take  for  granted — that  our  start  in  life  is  no 
haphazard  affair,  but  rigorously  determined  by  our 
parents  and  ancestors ;  that  various  peculiarities, 
important  and  trivial,  useful  and  disadvantageous, 
reappear  as  part  of  the  inheritance  generation 
after  generation. 

This  demonstration  of  heritability  is  still  going 
on  in  reference  to  particular  qualities ;  thus  we 
have  Prof.  Karl  Pearson's  evidence  in  regard  to 
such  subtle  qualities  as  longevity  and  fecundity, 
and  his  indirect  proof  that  mental  qualities  illus- 
trate the  same  law  of  inheritance  as  bodily  qualities. 
It  is  very  desirable  that  more  data  should  be  accu- 
mulated in  regard  to  the  heritability  of  variations, 
whether  Darwin's  "  individual  variations,"  or  De 
Vries's  "  mutations."  On  the  whole,  however,  it 
may  be  said  that,  since  Darwin's  day,  sufficient 
evidence  has  been  gathered  to  justify  us  in  saying 
/  that  any  kind  of  character  which  appears  as  an 
inborn  feature  in  an  organism  may  be  transmitted 
to  the  next  generation. 

(2)  "  Heredity "  a   Term  for   the  Genetic  Rela- 

1  See,  for  a  detailed  discussion  of  what  is  dealt  with  briefly  in 
this  chapter,  the  author's  treatise  "  Heredity  "  (Murray.  London, 
1908). 


FACTS    OF   INHERITANCE  131 

tion  between  Successive  Generations. — Another  step 
is,  that  we  are  learning  not  to  spell  heredity 
with  a  capital  "  h."  We  no  longer  think  of  it 
as  a  power  or  as  a  principle,  as  a  fate  or  as 
one  of  the  forces  of  nature  ;  we  study  it  as  a 
genetic  relation  which  is  sustained  by  a  visible 
material  basis,  as  a  relation  of  resemblances  and 
differences  which  can  be  measured  and  weighed,  or 
in  some  way  computed.  In  regard  to  property 
there  is  a  clear  distinction  between  the  heir  and 
the  estate  which  he  inherits ;  but  at  the  beginning 
of  an  individual  life  there  is  biologically  no  such 
distinction.  The  organism  and  its  inheritance  are, 
to  begin  with,  one  and  the  same.  We  inherit  our- 
selves. Thus  "  heredity  "  is  simply  a  convenient  term 
for  the  genetic  relation  between  successive  generations, 
and  inheritance  includes  all  that  the  organism  is,  or 
has,  to  start  with  in  virtue  of  its  hereditary  relation. 

(3)  Appreciation  of  Distinction  between  "  Nature  " 
and  "  Nurture." — Another  step,  following  on 
the  last,  is  that  we  have  begun  to  realise  more 
clearly  the  distinction  implied  in  the  words 
"  nature  "  and  "  nurture  " — a  distinction  made 
by  Shakespeare  and  definitised  by  Galton.  The  *, 
fertilised  egg-cell  contains,  in  some  way  which 
we  cannot  picture,  the  potentiality  of  a  particular  ; 
living  creature — a  tree,  a  daisy,  a  horse,  a  man.  I 
If  this  inheritance  is  to  be  realised  there  must  be 
an  appropriate  environment,  supplying  food  and 
oxygen  and  necessary  stimuli  of  many  kinds.  With- 
out this  nurture  the  inherited  nature  can  achieve 
nothing.  The  development  of  every  character 
implies  the  interaction  of  the  two  sets  of  factors — 
the  internal  organisation  and  the  external  environ- 
ment. But  the  surrounding  influences  are  often  very 


132       DARWINISM   AND    HUMAN    LIFE 

changeful,  and  the  nature  of  the  young  organism 
may  be  profoundly  modified  by  them.  Thus  we 
try  to  distinguish — and  it  is  of  enormous  practical 
as  well  as  theoretical  importance — between  the 
expression  of  hereditary  nature  realised  in  normal 
nurture  and  the  individually  acquired  modifica- 
tions which  are  due  to  changes  or  peculiarities  in 
that  nurture.  The  characters  of  a  newly  hatched 
chick  stepping  out  of  the  imprisoning  egg-shell  are 
in  the  main  strictly  hereditary  ;  but  they  need  not 
be  altogether  so,  for  during  the  three  weeks  before 
hatching  there  has  been  some  opportunity  for 
peculiarities  in  the  environment  to  leave  their 
mark  on  the  developing  creature.  Still  more  is 
this  the  case  with  the  typical  mammalian  embryo, 
which  develops  often  for  many  months  as  a  sort  of 
internal  parasite  within  the  mother,  in  a  complex 
and  variable  environment.  And  as  life  goes  on, 
peculiarities  due  to  nurture  continue  to  be  super- 
imposed on  the  hereditary  qualities,  especially 
when  the  creature  trades  with  time,  and,  by  choosing 
its  own  nurture,  creates  for  itself  an  individuality. 
(4)  The  Idea  of  the  Continuity  of  Generations. 
— Another  step  is  the  general  acceptance  of  a 
somewhat  subtle  and  yet  essentially  simple  idea, 
,  which  may  be  called  the  continuity  of  genera- 
'  tions.1  There  is  a  sense,  Galton  says,  in  which 
the  child  is  as  old  as  the  parent,  for  when  the 
',  parent's  body  is  developing  from  the  fertilised 
\  ovum  a  residue  of  unaltered  germinal  material  is 

1  In  his  address  "  Fifty  Years  of  Darwinism,"  Prof.  Poulton  says  : 
"  The  greatest  change  in  evolutionary  thought  since  the  publication 
of  the  '  Origin  '  was  wrought,  after  Darwin's  death,  by  the  appear- 
ance of  that  wonderful  and  beautiful  theory  of  heredity,  which 
looks  on  parents  as  the  elder  brother  and  sister  of  their  children." 


FACTS    OF   INHERITANCE  133 

kept  apart  to  form  the  reproductive  cells,  one  of 
which  may  become  the  starting-point  of  a  child. 
In  many  cases,  scattered  through  the  animal 
kingdom,  from  worms  to  fishes,  the  beginning  of  the 
lineage  of  germ-cells  is  demonstrable  in  very  early 
stages  before  the  division  of  labour  implied  in 
building  up  the  body  has  more  than  begun.  Let  us 
suppose  that  the  fertilised  ovum  has  certain 
qualities,  a,  6,  c,  .  .  .  x,  y,  z  ;  it  divides  and  re- 
divides,  and  a  body  is  built  up ;  the  cells  of  this 
body  exhibit  division  of  labour  and  the  structural 
side  of  this,  which  we  call  differentiation ;  they 
lose  their  likeness  to  the  ovum  and  to  the  first 
results  of  the  cleavage  of  the  ovum.  In  some  of 
the  body-cells  the  qualities  a,  b  find  predominant 
expression  ;  in  others  the  qualities  y,  z ;  and  so 
on.  But  if,  meanwhile,  there  be  certain  germ- 
cells  which  do  not  differentiate,  which  retain  the 
qualities  a,  b,  c,  .  .  .  x,  y,  z  unaltered,  these  will 
be  in  a  position  by-and-by  to  develop  into  an 
organism  like  that  which  bears  them.  Similar 
material  to  start  with,  similar  conditions  in  which 
to  develop — therefore,  like  tends  to  beget  like.  To 
use  Weismann's  words  :  "In  development  a  part 
of  the  germ-plasm  (i.e.  the  essential  germinal 
material)  contained  in  the  parent  egg-cell  is  not 
used  up  in  the  construction  of  the  body  of  the 
offspring,  but  is  reserved  unchanged  for  the  forma- 
tion of  the  germ-cells  of  the  following  generation." 
Thus  the  parent  is  rather  the  trustee  of  the  germ- 
plasm  than  the  producer  of  the  child.  In  a  new 
sense,  the  child  is  a  '  chip  of  the  old  block/  ' 

May  we  think  for  a  moment  of  a  baker  who  has    \ 
a  very  precious  kind  of  leaven  ;  he  uses  part  of  this 
in  baking  a  large  loaf ;  but  he  so  arranges  matters, 


134        DARWINISM    AND    HUMAN    LIFE 

by  a  curious  contrivance,  that  part  of  the  original 
leaven  is  not  mixed  up  with  the  dough,  but  is 
carried  on  unaltered  within  the  loaf,  carefully 
preserved  for  use  in  another  baking.  Nature  is 
the  baker,  the  loaf  is  a  body,  the  leaven  is  the  germ- 
plasm,  and  each  baking  is  a  generation. 

Picture  the  long  runner  of  a  strawberry,  bearing 
rooted,  flowering  plants  at  intervals :  the  runner 
may  represent  the  continuous  line  of  germ-cells, 
the  flowering  plants  are  the  individuals,  and  the 
relation  between  them  is  the  relation  of  genetic 
continuity,  which  we  call  heredity. 

It  will  be  obvious  that  this  concept  of  germinal 
continuity  is  very  different  from  Darwin's  pro- 
visional hypothesis  of  pangenesis,  according  to 
which  the  germ-cells  have  their  peculiar  virtue  of 
reproducing  like  from  like  because  they  become 
the  storehouses  of  representative  gemmules  liber- 
ated from  the  various  organs  of  the  body.  Although 
the  hypothesis  did  not  at  the  time  obtain  favour 
and  is  less  acceptable  now  than  ever,  it  is  interesting 
to  note,  as  Prof.  Strasburger  points  out,  that  it  in- 
cluded the  favourite  modern  idea  of  invisible  units 
as  the  carriers  of  particular  hereditary  characters. 

(5)  Critical  Attitude  in  regard  to  Various  Con- 
clusions.— Another  change  is  seen  in  the  critical 
attitude  which  is  now  taken  up  in  regard  to 
various  sets  of  facts,  or  alleged  facts,  relating  to 
inheritance,  which  were  once  accepted  without 
question.  Thus  Darwin  said  a  good  deal  about 
reversion  ;  but  many  phenomena  labelled  "  rever- 
sion "  have  received  a  different  interpretation,  and 
some  of  the  leading  authorities  on  heredity  have 
ceased  to  use  the  term.  It  is  difficult  to  find  a 
scientific  worker  who  believes  in  what  many 


FACTS    OF   INHERITANCE  135 

practical  men  put  money  on — the  influence  of  a 
previous  sire  on  offspring  subsequently  borne 
by  the  same  mother  to  a  different  father.  More 
serious,  however,  is  the  wide-spread  scepticism  as 
to  the  transmission  of  individually  acquired  charac- 
ters or  modifications. 

(6)  Mendelism. — But  the  greatest  change  that 
has  come  about  since  Darwin's  day  is  the  most 
recent l  one — associated  with  the  work  of  Mendel. 
We  shall  devote  some  attention  to  this  at  a  later 
stage  in  our  exposition,  but  it  may  be  noted, 
in  the  meantime,  that  Mendelian  experiment 
has  afforded  evidence  that  an  inheritance  often 
consists,  in  part  at  least,  of  well-defined,  non- 
blending  "  unit  characters/'  "  By  a  unit  character 
in  the  sense  of  Mendel's  law  we  mean  any  quality 
or  part  of  an  organism,  or  assemblage  of  qualities 
or  parts,  which  can  be  shown  to  be  transmitted 
in  heredity  as  a  whole  and  independently  of  other 
qualities  or  parts."  2  The  inheritance  in  a  fertilised 
egg-cell  consists  of  an  assemblage  of  distinct 
ingredients  in  duplicate,  contributed  from  the 
father  and  from  the  mother.  If  both  the  germ- 
cells  (egg-cell  and  sperm-cell)  bring  in  a  similar 
ingredient  when  they  unite  in  fertilisation,  then 
all  the  germ-cells  of  the  offspring  will  have  it ; 
if  neither  bring  it  in,  then  none  of  the  germ-cells 
of  the  offspring  will  have  it.  Two  blue-eyed 
parents  (without  pigment  in  the  front  of  the 
iris)  do  not  have  dark-eyed  children.  If  the 

1  We  must  say  recent,  for  although  Mendel  died  two  years  after 
Darwin  and  published  his  great  discovery  in  1865,  his  work  was  lost 
sight  of  till  1900,  when  Correns,  Tschermak,  and  De  Vries  were 
independently  led  to  a  rediscovery  of  Mendel's  law  and  to  a  dis- 
covery of  his  buried  memoirs. 

2  W.  E.  Castle,  in  "  Fifty  Years  of  Darwinism  "  (1909),  p.  146, 


136       DARWINISM   AND    HUMAN   LIFE 

ingredient  come  in  from  one  side  and  not  from 
the  other,  then,  on  an  average,  in  half  the  resulting 
germ-cells  it  will  be  present,  and  from  half  it 
will  be  absent.  "  This  last  phenomenon,  which 
is  called  segregation,  constitutes  the  essence  of 
Mendel's  discovery." 1  "  In  this/'  Mr.  Punnett 
says,  "  lies  the  explanation  of  the  facts  that 
hybrids  mated  together  produce  a  definite  pro- 
portion of  the  pure  forms,  which  subsequently 
breed  true  without  ever  giving  a  hint  of  their 
mixed  ancestry." 

METHODS  OF  STUDYING  HEREDITY. — In  studying 
a  difficult  problem,  such  as  the  weather,  there 
are  three  possible  lines  of  attack :  we  may  make 
minute  researches,  e.g.  on  the  role  of  dust  in 
forming  fog ;  we  may  make  experiments,  e.g.  on 
the  change  of  a  cloud  into  rain,  or  on  the  effect 
of  tree-planting  on  climate ;  or  we  may  collect 
a  multitude  of  observations  of  a  statistical  char- 
acter, e.g.  as  to  the  rainfall  in  different  localities 
and  at  different  times  of  year.  These  are  three 
sound  methods,  which  have  been  worked  with 
success.  They  are  complementary,  not  opposed. 

Similarly,  we  may  attack  the  problems  of 
heredity  by  the  microscopical  study  of  the  germ- 
cells  in  which  life  is  continued  from  generation 
to  generation,  by  breeding  experiments,  and  by 
the  statistical  study  of  the  measurable  characters 
of  successive  generations.2  These  three  different 
methods  of  attacking  the  problems  of  heredity 

1  W.  Bateson,  "  The  Methods  and  Scope  of  Genetics  "  (Cambridge, 
1908),  p.  15. 

2  It  is  of  interest  to  note  that  Sir  Francis  Galton,  who  may  be 
taken  as  the  representative  of   the  statistical  study,  and  Gregor 
Mendel,  who  was  the  pioneer  of  the  experimental  study,  were  born 
in  the  same  year  (1822). 


FACTS    OF   INHERITANCE  137 

seem  to  be  equally  valid,  and  though  the  generalisa- 
tions reached  along  the  different  lines  do  not  at 
present  cohere  in  a  harmonious  body  of  doctrine, 
there  is  no  reason  to  doubt  that  this  will  gradually 
develop.  Let  us  illustrate  some  of  the  results 
attained  along  the  three  lines. 

MICROSCOPICAL  STUDY  OF  THE  GERM-CELLS. — 
Most  plants  and  animals  are  built  up  of  cells 
and  start  in  life  as  fertilised  egg-cells,  and  it 
was  in  a  fertilised  egg-cell  that  our  own  natural 
inheritance  consisted.  A  few  exceptions  may  be 
made — e.g.  for  bananas,  which  have  no  longer 
any  seeds ;  for  potatoes,  which  are  multiplied  by 
cutting;  for  the  drone-bees  and  summer  green- 
flies, which  have  mothers  but  no  fathers;  and 
for  the  simple,  single-celled  organisms  which  are 
themselves  comparable  to  eggs  and  sperms ;  but 
the  exceptions  are  trivial  compared  with  the 
vast  majority  of  living  creatures  of  which  it  is 
certain  that  each  individual  life  begins  as  a  ferti- 
lised egg-cell — the  result  of  the  intimate  and 
orderly  union  of  a  spermatozoon  and  an  ovum. 

We  get  a  very  misleading  idea  of  the  ovum,  or 
egg-cell,  when  we  think,  as  we  always  do  at  first, 
of  birds'  eggs.  For  in  these  familiar  objects  the 
true  egg-cell  has  been  dilated  by  an  enormous 
quantity  of  nutritive  yolk,  on  the  top  of  which 
a  minute  drop  of  nucleated  living  matter  lies 
like  an  inverted  watch-glass.  Most  ova  are  very 
minute  cells,  often  invisible  to  the  naked  eye. 
The  spermatozoon,  or  male  element,  which  fertilises 
the  egg,  is  smaller  still ;  it  is  often  only  10Q000  th 
of  the  ovum's  size.  In  a  way  that  we  cannot 
picture  each  of  the  germ-cells  (or  gametes)  carries  a 
complete  set  of  hereditary  characters.  All  theory 


138       DARWINISM   AND    HUMAN   LIFE 

apart,  it  is  by  the  minute  germ-cells  that  the 
secret  of  life  and  the  character  of  each  kind  of 
living  creature  are  sustained  from  generation  to 
generation.  Within  every  cell  in  the  body  of 
an  organism  there  is  usually  a  nucleus,  and  within 
the  nucleus  a  number — a  definite  number — of 
readily  stainable  rods,  or  loops,  or  grains  called 
chromosomes.  Each  kind  of  living  creature  has 
a  definite  number ;  thus,  there  are  thirty-two  in 
man  and  in  the  cockroach,  twenty-four  in  mouse 
and  in  lily,  twelve  in  the  grasshopper,  and  two  in 
a  species  of  threadworm.  There  is  no  doubt  that 
these  stainable  bodies,  or  chromosomes  (including 
less  visible  bodies  associated  with  them),  are  very 
important.  There  are  many  facts  pointing  to  the 
conclusion  that  they  are  bearers  (not  perhaps  the 
exclusive  bearers)  of  specifically  different  materials 
which,  in  appropriate  conditions,  will  develop  into 
particular  heritable  qualities.  One  of  the  leaders 
of  experimental  zoology,  Dr.  Przribram,  sums  up 
a  number  of  remarkable  investigations  when  he 
says :  "  Substances  or  parts  can  be  actually 
demonstrated  in  the  ovum,  the  removal  of  which 
conditions  the  absence  of  definite  organs  or  parts  in 
the  embryo/'  Now,  while  the  immature  germ-cells 
have  the  same  number  of  chromosomes  as  the 
cells  of  the  body  have,  the  mature  germ-cells  have 
half  the  normal  number.  If  8  be  the  normal 
number,  the  ripe  ovum  has  4,  and  the  fully  formed 
spermatozoon  has  4,  so  that  when  the  ovum  is 
fertilised  the  normal  number  is  restored.  In  a 
remarkable  way,  by  a  kind  of  cell-division  which 
occurs  only  in  the  maturing  germ-cells,  the  number 
of  chromosomes  is  always  reduced  by  a  half — 
except,  indeed,  in  certain  cases  of  parthenogenesis. 


FACTS    OF   INHERITANCE  139 

In  this  reduction,  which  means  in  the  case  of  the 
egg  the  absolute  rejection  of  half  of  the  chromo- 
somes (which  are  carried  off  by  the  first  polar 
body  and  come  to  nothing),  we  see  an  opportunity 
for  permutations  and  combinations  among  the 
items  of  the  inheritance,  e.g.  for  the  dropping  out 
of  a  character  altogether. 

Not  less  important  is  the  visibly  demonstrable 
fact  that  sperm  and  ovum  contribute  the  same 
number  of  chromosomes  (except  in  certain  cases 
where  half  of  the  spermatozoa  have  an  extra 
chromosome),  and  that,  when  the  fertilised  egg- 
cell  divides,  each  daughter-cell  receives  the  normal 
number  of  chromosomes,  half  of  maternal  origin 
and  half  of  paternal  origin.  This  has  been  followed 
for  several  divisions,  so  that,  if  the  chromosomes 
are  inheritance-bearers,  we  have  ocular  demonstra- 
tion of  the  truth  of  the  prophetic  statement  which 
Huxley  made  in  1878  :  "  It  is  conceivable,  and 
indeed  probable,  that  every  part  of  the  adult 
contains  molecules  derived  both  from  the  male 
and  from  the  female  parent ;  and  that,  regarded 
as  a  mass  of  molecules,  the  entire  organism  may 
be  compared  to  a  web  of  which  the  warp  is 
derived  from  the  female  and  the  woof  from  the 
male." 

STATISTICAL  STUDY  :  FILIAL  KEGRESSION. — 
Darwin's  illustrious  cousin,  Sir  Francis  Galton, 
has  been  the  leader  in  the  statistical  study  of 
inheritance.  He  has  shown  the  value  of  collecting 
statistics  as  to  the  resemblances  and  differences 
in  successive  generations,  e.g.  as  regards  stature, 
colour  of  eyes,  and  intellectual  ability,  and  he 
has  reached  several  general  inductions  which 
express  the  inherent  orderliness  obtaining  even 


140       DARWINISM   AND    HUMAN   LIFE 

in  a  domain  where  occurrences  seem  as  capricious 
as  those  of  weather. 

It  has  often  been  remarked  that  the  children 
of  extraordinarily  gifted  parents  are  sometimes 
very  ordinary  individuals,  and  that  the  children 
of  under-average  parents  sometimes  turn  out 
surprisingly  well,  both  physically  and  mentally. 
Every  one  who  has  looked  into  the  facts  of  in- 
heritance in  greater  detail,  and  has  compared  the 
average  of  qualities  in  successive  generations, 
has  noticed,  in  a  general  way,  that  there  is  a 
tendency  to  sustain  the  same  average  level  from 
generation  to  generation.  Even  the  older  in- 
quirers, like  Lucas,  called  attention  to  the  fact 
that  extraordinary  qualities  in  families  tend  to 
wane  away,  as  if  there  were  some  mysterious 
succession-tax  levied  on  marked  deviations  from 
the  average,  whether  in  the  way  of  excellence  or 
of  defect.  But  we  owe  to  Galton's  careful  statisti- 
cal work  the  generalisation  known  as  the  Law  of 
Filial  Regression,  which  has  replaced  a  vague 
impression  by  a  definite  formula.  He  has  defined 
and  measured  the  tendency  towards  mediocrity, 
the  tendency  to  approximate  to  the  mean,  or 
average,  of  the  stock.  We  must  notice,  at  the 
outset,  that  this  Filial  Regression  has  nothing  to 
do  with  reversion  or  with  degeneration,  that  it 
works  upwards  as  well  as  downwards,  forwards 
as  well  as  backwards. 

The  data  which  Galton  utilised  were  chiefly  the 
records  of  family  faculties,  obtained  from  about 
one  hundred  and  fifty  families,  and  dealing  especi- 
ally with  stature,  eye-colour,  temper,  artistic 
faculty,  and  some  forms  of  disease.  These  were 
supplemented  by  measurements  at  Galton 's  anthro- 


FACTS    OF    INHERITANCE  141 

pometric  laboratory,  and  by  observations  on 
sweet-peas,  and  to  some  extent  on  moths. 

Most  trustworthy,  however,  were  the  data  pro- 
cured in  regard  to  stature,  which,  as  Galton  points 
out,  is  a  quality  with  many  advantages  as  a  subject 
of  investigation.  It  is  nearly  constant  during 
mature  life,  it  is  readily  and  frequently  measured 
with  accuracy,  and  it  does  not  seem  to  be  of  appre- 
ciable moment  in  sexual  selection.  Its  variability, 
though  small,  is  normal ;  that  is  to  say,  it  is  ex- 
pressible in  the  normal  curve  of  the  frequency  of 
error. 

As  the  subject  is  by  no  means  easy  to  those 
unaccustomed  to  statistical  inquiry,  and  as  we 
cannot,  within  our  limits,  explain  the  methods, 
it  may  be  most  profitable  to  give  a  few  illustrative 
quotations  from  Galton's  "  Natural  Inheritance  " 
(1889). 

"  If  the  word  '  peculiarity '  be  used  to  signify 
the  difference  between  the  amount  of  any  faculty 
possessed  by  a  man  and  the  average  of  that 
possessed  by  the  population  at  large,  then  the  law 
of  regression  may  be  described  as  follows.  Each 
peculiarity  in  a  man  is  shared  by  his  kinsmen, 
but  on  the  average  in  a  less  degree.  It  is  reduced 
to  a  definite  fraction  of  its  amount,  quite  inde- 
pendently of  what  its  amount  might  be.  The 
fraction  differs  in  different  orders  of  kinship, 
becoming  smaller  as  they  are  more  remote " 
(p.  194). 

"  However  paradoxical  it  may  appear  at  first 
sight,  it  is  theoretically  a  necessary  fact,  and  one 
that  is  clearly  confirmed  by  observation,  that  the 
stature  of  the  adult  offspring  must  on  the  whole  be 
more  mediocre  than  the  stature  of  their  parents ; 


142       DARWINISM    AND    HUMAN    LIFE 

that  is  to  say,  more  near  to  the  mean  or  mid  of  the 
general  population  "  (p.  95). 

"  The  law  of  regression  tells  heavily  against  the 
full  hereditary  transmission  of  any  gift.  Only  a 
few  out  of  many  children  would  be  likely  to  differ 
from  mediocrity  so  widely  as  their  mid-parents,1 
and  still  fewer  would  differ  as  widely  as  the  more 
exceptional  of  the  two  parents.  The  more  bounti- 
fully a  parent  is  gifted  by  nature,  the  more  rare 
will  be  his  good  fortune  if  he  begets  a  son  who  is  as 
richly  endowed  as  himself,  and  still  more  so  if  he 
has  a  son  who  is  endowed  yet  more  largely.  But 
the  law  is  even-handed ;  it  levies  an  equal  succes- 
sion-tax on  the  transmission  of  badness  as  of 
goodness.  If  it  discourages  the  extravagant  hopes 
of  a  gifted  parent  that  his  children  will  inherit  all 
his  powers,  it  no  less  discountenances  extravagant 
fears  that  they  will  inherit  all  his  weakness  and 
disease  "  (p.  106). 

"  It  must  be  clearly  understood  that  there  is 
nothing  in  these  statements  to  invalidate  the 
general  doctrine  that  the  children  of  a  gifted  pair 
are  much  more  likely  to  be  gifted  than  the  children 
of  a  mediocre  pair.  They  merely  express  the  fact 
that  the  ablest  of  all  the  children  of  a  few  gifted 
pairs  is  not  likely  to  be  as  gifted  as  the  ablest  of  all 
the  children  of  a  very  great  many  mediocre  pairs  " 
(p.  106). 

Nor  must  the  fact  of  regression  be  supposed 
to  affect  the  general  value  of  a  good  stock  or  the 
general  disadvantage  of  a  bad  one.  Two  gifted 
members  of  a  poor  stock  may  be  personally  equiva- 

1  The  mid-parent  is  a  statistical  fiction,  with  a  stature  half  that 
of  the  two  parents  when  allowance  is  made  for  the  average  difference 
of  stature  in  the  two  sexes. 


FACTS    OF   INHERITANCE  143 

lent  to  two  ordinary  members  of  a  good  stock, 
but  "  the  children  of  the  former  will  tend  to  re- 
gress ;  those  of  the  latter  will  not "  (p.  198). 

Let  us  give  a  concrete  illustration  from  Prof.  Karl 
Pearson's  "  Grammar  of  Science  "  (1900,  p.  454) : 
"  Fathers  of  a  given  height  have  not  sons  all  of  a 
given  height,  but  an  array  of  sons  of  a  mean  height 
different  from  that  of  the  father  and  nearer  to  the 
mean  height  of  sons  in  general.  Thus,  take  fathers 
of  stature  72  inches,  the  mean  height  of  their  sons 
is  70*8  in.,  or  we  have  a  regression  towards  the  mean 
of  the  general  population.  On  the  other  hand, 
fathers  with  a  mean  height  of  66  in.  give  a 
group  of  sons  of  mean  height  68*3  in.,  or  they  have 
progressed  towards  the  mean  of  the  general  popula- 
tion of  sons.  The  father  with  a  great  excess  of  the 
character  contributes  sons  with  an  excess,  but  a 
less  excess  of  it ;  the  father  with  a  great  defect 
of  the  character  contributes  sons  with  a  defect, 
but  less  defect  of  it.  The  general  result  is  a  sensible 
stability  of  type  and  variation  from  generation  to 
generation." 

There  seems  no  reason  to   doubt  the  general  ; 
occurrence  of  regression  towards  mediocrity,  though  \ 
the  law  requires  modification  in  regard  to  charac- 
ters which  are  subject  to  keen  selection,  either 
natural  or  sexual,  and  though  it  does  not  apply  to 
sharply  defined  "unit  characters"  which  do  not 
blend. 

GALTON'S  LAW  OF  ANCESTRAL  INHERITANCE. — 
It  is  necessary,  however,  to  ask  what  this  statis- 
tically established  fact  of  filial  regression  really 
means  biologically. 

In  all  ordinary  cases  of  reproduction  the  off- 
spring has  a  strictly  dual  or  bi-parental  inheritance. 


144       DARWINISM   AND    HUMAN   LIFE 

Whatever  the  inheritance  may  be  in  its  expression — 
whether  it  show  a  blend  or  takes  after  one  side  of  the 
house — it  is  made  up,  to  begin  with,  of  equal  con- 
tributions from  the  two  parents.  Obviously,  how- 
ever, if  the  concept  of  the  continuity  of  the  germ- 
plasm  be  correct,  the  contribution  from  the  father 
is  made  up  of  contributions  from  his  two  parents, 
and  the  contribution  from  the  mother  is  made  up 
of  contributions  from  her  two  parents.  And  so 
on  backwards.  Thus  we  reach  the  idea,  to  be 
corrected  in  cases  where  Mendelian  inheritance  has 
been  proved  for  particular  characters,  that  an 
individual  inheritance  is  a  mosaic  of  ancestral 
contributions.  Incidental  corroborations  of  this 
fruitful  idea  are  familiar  to  all — e.g.  in  the  re- 
expression  of  peculiarities  which  were  characteristic 
of,  say,  a  grandfather  or  a  great-grandmother. 

But  we  owe  to  Galton's  careful  statistical  work, 
as  to  stature  and  other  qualities  in  man,  and  as 
to  coat-colour  in  Basset  hounds,  a  generalisation 
which  formulates  the  share  which  the  various 
ancestors  have,  on  an  average,  in  the  inheritance 
of  any  individual  organism.  This  Law  of  Ancestral 
Inheritance  is  as  follows :  "  The  two  parents 
between  them  contribute,  on  the  average,  one-half 
of  each  inherited  faculty,  each  of  them  contributing 
one-quarter  of  it.  The  four  grandparents  con- 
tribute between  them  one-quarter,  or  each  of  them 
one-sixteenth ;  and  so  on,  the  sum  of  the  series 
J  +  i  +  s  +  A  +  •  •  •  »  being  equal  to  1,  as 
it  should  be.  It  is  a  property  of  this  infinite 
series  that  each  term  is  equal  to  the  sum  of  all 
those  that  follow :  thus  J  =  J  +  J+  &  +  ..., 
J  =  J  +  rg  -f  .  .  .  ,  and  so  on.  The  prepo- 
tencies or  subpqtencies  of  particular  ancestors,  in 


FACTS    OF   INHERITANCE  145 

any  given  pedigree,  are  eliminated  by  a  law  that 
deals  only  with  average  contributions,  and  the 
varying  prepotencies  of  sex  in  respect  to  different 
qualities  are  also  presumably  eliminated."  Thus 
an  inheritance  is  not  merely  dual,  but  through  the 
parents  it  is  multiple,  and  the  average  contribu- 
tions made  by  grand-parents,  great-grandparents, 
etc.,  are  definite,  and  diminish  in  a  precise  ratio 
according  to  the  remoteness  of  the  ancestors. 

EXPERIMENTAL  STUDY. — Perhaps  we  may  most 
profitably  illustrate  the  experimental  study  of 
heredity  by  asking  what  the  possible  results  are 
of  pairing  two  hypothetical  organisms.  Although 
prediction  as  to  the  result  of  any  individual  pairing 
is  apt  to  be  falsified  (except  in  clear  cases  of 
Mendelian  inheritance),  there  are  some  well- 
known  alternatives  of  expectation. 

(1)  Pairing   of  Similar  Pure-bred  Forms. — Let 
us  begin  with  the  offspring  of  similar  pure-bred 
organisms.    When  similar  forms  are  bred  together 
for  several  generations  a  certain  uniformity  of  type 
is  likely  to  result.     If  by  selection  the  most  similar 
are  mated  together,  while  the  least  similar  are 
persistently  removed  from  the  stock,  and  if  there 
is  also  some  measure  of  inbreeding,  then  there  is 
likely  to  be  more  or  less  constant  uniformity  of 
type.      These    "  pure-bred "    organisms   produce 
others  like  themselves,  and  we  suppose  this  to  mean 
that  the  hereditary  items  in  the  ovum  have  not 
only  their  counterpart,  but  their  equivalent,  among 
the  hereditary  items  in  the  spermatozoon.     This, 
then,  is  one  of  the  modes  of  inheritance — that  the  off- 
spring closely  resemble  the  parents  and  one  another. 
The  variability  is  restricted  within  a  small  range. 

(2)  Blending. — Passing     from    the    mating    of 

10 


146       DARWINISM   AND    HUMAN    LIFE 

similar  pure-bred  organisms  to  other  cases,  we  note, 
as  a  frequent  occurrence,  that  the  offspring  is  a 
combination  of  the  paternal  and  maternal  charac- 
teristics in  such  a  thoroughgoing  way  that  the 
result  may  be  described  as  an  intimate  blend.  In  a 
cross  between  the  long-eared  lop-rabbit  and  a  short- 
eared  breed,  Castle  found  that  forms  with  ears  of 
intermediate  length  are  produced,  and  that  these 
intermediates  breed  true.  The  colour  of  the  skin 
in  mankind  seems  to  blend  when  white  and  black 
races  are  crossed.  Many  plant  hybrids  are  precisely 
intermediate  between  the  two  parents. 

(3)  Particulate  Inheritance. — The  offspring  often 
show  what    may   be  called  a  coarse-grained  or 
non-blended    combination    of    the    paternal    and 
maternal  characteristics,  the  former  appearing  in 
one  part  of  the  body,  the  latter  in  another  part,  as 
when  a  light-coloured  horse  and  a  dark-coloured 
mare  have  a  piebald  foal,  or  when  a  sheep-dog  has 
an  eye  like  its  father  on  one  side  and  an  eye  like  its 
mother  on  the  other  side.     This  is  often  described 
as  particulate  inheritance. 

(4)  Exclusive    Inheritance. — It   often   happens 
that  the  offspring  takes  wholly  after  one  of  its 
parents,  or  wholly  as  regards  particular  organs, 
and  extreme  forms  of  this  are  spoken  of  as  exclusive 
inheritance.    The    inheritance   of    eye-colour    in 
mankind  belongs    to    this   type.     Although    the 
inheritance  is  dual,  it  seems  as  if  only  one  set  of 
the  heritable  characters  found  expression — at  least 
as  regards  particular  organs.     The  more  pure-bred 
parent  is  the  more  likely  to  be  prepotent  in  the 
inheritance.     This  exclusive  inheritance  may  be 
the  first  step  in  a  clear  Mendelian  case,  which  we 
shall  consider  later. 


FACTS    OF   INHERITANCE  147 

(5)  Reversion. — Another    mode    of    inheritance 
— known  as  Eeversion — is  seen  when  the  offspring 
exhibits  features  which  were  not  expressed  in  its 
immediate   ancestry,    but   were   characteristic   of 
more  remote  ancestry,  as  when  crossing  different 
races  of  pigeons,  which  have  been  breeding  true, 
results  in  the  production  of  the  ancestral  rock- 
dove  type.    Professor  Cossart  Ewart  crossed  an 
"  Owl "  with  an  "  Archangel "  and  obtained  a 
hybrid  more  like  the  former  than  the  latter.     He 
crossed  this  with  a  prepotent  white  fantail  and 
obtained  two  pigeons  closely  resembling  the  wild 
rock-dove    type.     Darwin    laid    stress    on    such 
reversionary  Blue  Rocks  which  occur  when  widely 
differing  breeds  are  crossed  and  the  hybrids  are 
bred  together,  but  some  recent  experiments,  e.g. 
those  of  Staples-Browne,  suggest  that  there  may 
be  a  Mendelian  interpretation  even  of  Darwin's 
classic  cases  of  reversion.     The  case  of  rabbits  is 
very  suggestive.     When  rabbits  of  different  colours 
are  turned  loose  and  breed  together,  their  descend- 
ants  tend   to   be   eventually    all   grey.    Darwin 
regarded  this  as  a  reversion,  and  it  may  still  be 
described  as   reversionary;    but  it  is  not  due  to 
the  reassertion  of  long  latent  grey  colouring.     The 
return  to  grey  is  due,  as  the  Mendelian  experiments 
show,    to    the   recombination   of    at   least   eight 
colour-ingredients    that    go    to    the    make-up    of 
wild  greyness.     Man  has  sifted  out  all  the  various 
colours  from  the  complex  coloration  of  the  wild 
stock,   and   when   the   long-separated   items   are 
brought    together    again    by    unrestricted    inter- 
breeding there  is,  naturally  enough,  a  reconstruction 
of  the  original  grey  colour. 

(6)  New    Departures. — Just    as    we    began    by 


148       DARWINISM   AND   HUMAN   LIFE 

noting  that  the  offspring  of  carefully  pure-bred 
types  might  be  almost  replicas  of  the  parents, 
so  we  must  notibe  the  opposite  extreme,  where 
the  offspring  represent  something  quite  new — a 
novel  position  of  organic  equilibrium— a  "  freak/' 
or  "  sport,"  or  "  mutation,"  or  "  discontinuous 
variation."  That  these  new  departures  have  some- 
times formed  the  beginning  of  a  new  domesticated 
breed  or  cultivated  variety  is  well  known ;  and 
it  is  possible  that  species  in  nature  may  sometimes 
have  arisen  in  a  similar  way. 

(7)  Mendelian  Inheritance. — In  typical  cases 
of  Mendelian  inheritance  we  have  to  do  with  the 
pairing  of  two  pure-bred  types  which  differ  from 
one  another  in  respect  of  one  or  more  unit  char- 
acters, which  may  be  obvious  qualities,  such  as 
colour  and  markings,  or  more  subtle  qualities, 
such  as  the  loaf -producing  "  strength  "  of  wheat, 
its  susceptibility  or  immunity  in  respect  to  rust, 
the  broodiness  or  non-broodiness  of  poultry, 
the  horned  or  hornless  state  of  the  head  in 
cattle. 

The  result  of  the  crossing  is  that  the  "  hybrid  " 
progeny  all  resemble  one  parent  in  respect  of 
the  contrasted  characters.  There  are  no  inter- 
mediates, for  Mendelian  characters  do  not  blend. 
The  offspring  of  grey  and  white  mice  are  all  grey ; 
the  offspring  of  giant  and  dwarf  peas  are  all  tall ; 
and  so  on.  It  is  usual  to  speak  of  the  character 
that  persists  and  is  expressed  as  the  dominant 
character,  while  that  which  remains  unexpressed 
or  latent  is  called  recessive. 

But  when  the  "  hybrids  "  are  inbred,  the  next 
generation  shows  a  reappearance  of  the  original 
parental  types  both  dominant  and  recessive — 


FACTS    OF   INHERITANCE  149 

both  breeding  true — and  a  number  of  forms, 
usually  like  pure  dominants,  which,  when  inbred, 
again  produce  "  pure  dominants,"  "  pure 
recessives,"  and  "  impure  dominants  "  like  them- 
selves. In  typical  cases,  where  attention  is  paid 
to  one  pair  of  contrasted  characters,  the  proportions 
of  the  "  hybrids "  always  approximate  to  the 
formula — 1  pure  dominant :  2  impure  dominants  : 
1  pure  recessive. 
This  may  be  expressed  in  a  simple  schema  : 


.  .  Parents 
Hybrids.    F1 


I  I  I 

1DD       +     2D(R)  +        1RR        2nd  Generation  Fa 
Extracted         Impure  Extracted 

Pure          Dominants  Pure 

Dominants         x  x  Recessives 


DD       1DD  +  2D(R)  +  RR         RR       3rd  Generation  F* 

Mendel  explained  his  results  by  the  ingeniously 
simple  hypothesis  of  segregation.  He  supposed 
that  the  germ-cells  of  the  hybrids  segregated  into 
two  contingents,  one  half  bearing  the  dominant 
character  and  one  half  bearing  the  recessive 
character.  If  fertilisations  follow  the  laws  of 
chance  the  second  generation  should  theoretically 
show  the  proportions  which  actually  occur.  When 
there  are  two  pairs  of  contrasted  characters — 
for  instance,  when  a  tall  yellow-seeded  (Dd)  pea 
is  crossed  with  a  dwarf  green-seeded  one  (Rr) — 
the  offspring  are  tall  yellows  (Dd),  combining  the 


150       DARWINISM   AND    HUMAN    LIFE 

two  dominant  features ;  and  when  these  are  self- 
fertilised  (which  is  equivalent  to  inbreeding), 
out  of  16  offspring  there  are  9  tall  yellows  (Dd), 
3  tall  greens  (Dr),  3  dwarf  yellows  (Rd),  and  one 
dwarf  green  (Rr).  When  a  rabbit  of  the  wild 
grey  colour  is  crossed  with  an  albino,  the  offspring 
are  all  grey,  and  these,  if  bred  together,  give  in 
certain  cases  9  greys,  3  blacks,  and  4  albinos, 
which  is  a  slight  modification  of  the  ordinary 
9:3:3,  1  ratio  due  to  the  impossibility  of  dis- 
tinguishing, by  external  appearance,  between  two 
different  kinds  of  albino. 

UNIT  CHARACTERS. — We  do  not  at  present  know 
with  certainty  how  many  qualities  and  parts  can 
be  called  "  unit  characters "  in  the  Mendelian 
sense.  The  only  criterion  is  the  experimental  one  : 
can  the  character  be  lost,  as  a  whole,  in  cross- 
breeding ?  Prof.  W.  E.  Castle  l  gives  an  illustra- 
tion :  "  If  we  cross  a  black  guinea-pig  with  one 
which  lacks  black — say  a  brown  one — we  obtain 
only  black  offspring ;  but  these  bred  inter  se  produce 
black  offspring  and  brown  ones,  in  the  proportion 
three  black  to  one  brown.  We  thus  learn  that 
black  is  a  unit  character.  It  was  contributed  by 
one  parent  to  the  cross,  but  not  by  the  other,  and 
transmitted  by  the  cross-bred  individual  to  half 
its  offspring,  but  not  to  the  other  half.  This  is 
Mendel's  explanation  of  the  3 :  1  ratio,  now 
familiar  to  every  biologist. 

"  But  if  we  cross  the  same  black  parent  in  the 
foregoing  case,  not  with  a  brown  individual,  but 
with  a  white  one  or  with  a  yellow  one,  we  may 
obtain,  not  black  offspring,  but  wild-coloured 

1  "  The  Behaviour  of  Unit  Characters  in  Heredity,"  in  "  Fifty 
Years  of  Darwinism  "  (1909),  p.  148. 


FACTS    OP   INHERITANCE  151 

'  agouti '  ones,  which  bred  inter  se  will  produce 
agouti,  black,  white  (or  else  yellow)  young,  with 
perhaps  those  of  other  new  classes  in  addition. 
Such  a  result  as  this  puzzled  Darwin,  and  would 
naturally  puzzle  any  one  ;  but  in  the  light  of 
Mendel's  law  becomes  capable  of  ready  explanation. 
The  production  of  black  pigment  is  a  process  in 
which  more  than  one  unit  character  is  concerned, 
the  production  of  a  grey  coat  involves  more 
units  still.  .  .  .  What  was  unknown  to  Mendel 
has  been  made  clear  since  1900:  that  in  many 
cases  two  or  more  independent  unit  characters 
must  be  present  to  produce  a  single  visible 
effect/' 

THE  CASE  OF  ANDALUSIAN  FOWLS. — The  pheno- 
mena of  Mendelian  inheritance  are  well  illustrated 
in  the  case  of  the  Blue  Andalusian  fowl.  We  quote 
Mr.  Punnett's  account l :  "  The  Andalusian  has  long 
been  known  to  possess  an  inconvenient  peculiarity  : 
it  will  not  breed  true.  It  always  throws '  wasters  ' 
of  two  sorts  :  blacks,  and  whites  marked  with  some 
black  splashes.  There  are,  therefore,  three  kinds 
of  Andalusians,  and  consequently  six  possible 
types  of  mating  among  these  three  varieties.  With 
regard  to  the  results  of  these  types  of  mating, 
careful  experiment  has  brought  out  the  following 
facts  : 

Blue  x  Blue  gives  Blacks,  Blues,  and  Whites,  in  the  ratiol :  2 : 1 . 
Blue  x  Black  ,  Blacks  and  Blues  in  equal  numbers. 


Blue  x  White  , 
Black  x  Black  . 
White  X  White  , 
Black  x  White , 


Blues  and  Whites  in  equal  numbers. 
Blacks  only. 
Whites  only. 
Blues  only. 


1  "  Mendelism   in    Relation  to    Disease,"    «« Proc,  Roy.    Soc. 
Medicine"  (March  1908). 


152       DARWINISM   AND    HUMAN    LIFE 

"  We  are  dealing  here  with  a  case  in  which  every 
possible  form  of  mating  has  been  carried  out,  and 
some  of  the  results,  at  first  sight,  seem  paradoxical. 
Thus,  for  instance,  the  blacks  always  breed  true, 
whatever  their  ancestry  may  have  been ;  and  the 
same  holds  good  for  the  whites.  The  white  that 
is  produced  by  two  blues,  themselves  the  product 
of  mating  blue  with  blue  over  many  generations, 
breeds  as  true  to  whiteness  as  the  white  of  pure 
white  ancestry.  A  black  is  pure  for  blackness  and 
a  white  is  pure  for  whiteness,  whatever  the  ancestry 
of  the  bird  may  have  been.  Again,  it  seems  at  first 
sight  incongruous  that  the  mating  of  black  with 
white  should  give  just  twice  as  many  blues  as  two 
blues  mated  together. 

"  We  are  dealing  with  an  alternative  pair  of 
characters,  blackness  and  whiteness.  Every  germ- 
cell,  or  gamete,  whether  ovum  or  spermatozoon, 
bears  a  representative  of  this  pair.  But  it  can 
bear  only  one  representative,  viz.  either  blackness 
or  whiteness.  Hence  for  this  pair  of  characters 
there  are  two,  and  only  two,  types  of  gamete  : 
'  black  '  gametes  and  '  white  '  gametes.  When 
a  black  gamete  meets  a  black  the  result  is  a  black 
bird ;  when  a  white  meets  a  white  the  result  is  a 
white  bird ;  but  when  a  white  meets  a  black  the 
resulting  zygote1  contains  the  representatives  or 
factors  for  both  blackness  and  whiteness,  and 
develops  into  a  blue  bird.  Now  we  must  suppose 
that  the  gametic  representative  of  a  character, 
the  factor,  is  an  unsplittable  entity  so  far  as 
inheritance  is  concerned.  The  zygote,  being 

1  Gamete  is  the  technical  term  for  a  germ-cell,  either  egg-cell 
or  sperm-cell ;  zygote  is  the  technical  term  for  the  egg-cell  after  it 
has  been  fertilised  by  the  sperm -cell. 


FACTS    OF    INHERITANCE  153 

formed  by  two  gametes,  must  contain  two  factors. 
It  is  a  double  structure,  and,  when  it  comes  to 
form  gametes,  these  single  structures  are  produced 
by  the  separation  of  the  two  factors  present  in 
any  zygotic  cell.  The  factors  representing  the 
characters  are  said  to  segregate  from  one  another  in 
the  process.  In  a  zygote  produced  by  the  union 
of  similar  gametes,  the  segregation  is  between  like 
factors,  and  all  the  gametes  produced  are  alike. 
But  a  zygote  which  has  been  formed  by  two 
dissimilar  gametes,  each  bearing  one  of  the  factors 
corresponding  to  a  pair  of  characters,  must,  on 
forming  gametes,  give  rise  to  gametes  of  two  sorts, 
and  must  give  rise  to  them  in  equal  numbers. 
On  this  simple  hypothesis  is  afforded  a  ready 
explanation  of  the  various  experimental  facts 
given  above. 

"  A  blue  hen  is  producing  equal  numbers  of 
'  black  '  and  *  white '  eggs — let  us  say  2n  of 
each.  To  fertilise  these  eggs  are  brought  large 
numbers  of  spermatozoa  of  the  two  sorts,  black  and 
white,  in  equal  numbers.  Every  black  egg,  then, 
has  an  equal  chance  of  being  fertilised  by  a  black 
or  a  white  spermatozoon.  In  the  former  case  it 
will  form  a  black,  and  in  the  latter  a  blue,  bird. 
From  our  2n  black  eggs  we  shall  obtain  n  black, 
and  n  blue  birds;  that  is  to  say,  the  mating  of 
blue  with  blue  must,  on  the  assumption  of  the 
purity  of  the  gametes,  give  black,  blue,  and  white 
in  the  ratio  1:2:  1." 

WALTZING  MICE. — Let  us  take  another  illustra- 
tion relating  to  the  quaint  Japanese  waltzing 
mice,  which  waltz  round  and  round  in  circles  and 
have  only  one  semicircular  canal  of  the  ear  well 
developed.  When  waltzing  mice  are  crossed  with 


154       DARWINISM   AND    HUMAN    LIFE 

normal  mice  all  the  progeny  are  normal.  The 
waltzing  habit  is  recessive,  the  normal  is  dominant. 
When  the  hybrids  are  inbred  the  resulting  genera- 
tion consists  of  normal  mice  and  waltzing  mice  in 
the  proportion  of  three  dominants  to  one  recessive. 
The  recessives  of  this  generation,  when  inbred, 
yield  only  recessives,  for  as  many  generations  as 
one  likes  to  breed  them.  The  dominants  are 
found  to  be  of  two  kinds  :  one-third  of  them — 
called  pure  dominants — when  inbred  yield  only 
dominants ;  the  other  two-thirds — called  impure 
dominants — yield  dominants  and  recessives  in  the 
old  proportions  of  3  :  1. 

It  is  supposed  that  the  hybrids  have  germ-cells 
of  two  kinds,  one  half  bearing  the  waltzing  charac- 
ter, the  other  the  normal  character.  Each  germ-cell 
is  "  pure  "  as  regards  this  character.  There  are 
twice  as  many  chances  of  the  unlike  combination 
occurring — that  is,  of  normal  and  waltzing — as  of 
the  like  combination  occurring — that  is,  of  normal 
meeting  normal,  or  waltzing  waltzing.  In  other 
words,  the  percentage  of  individuals  in  the  three 
groups  will  be  what  it  is:  25  pure  normal,  50 
impure  normal,  and  25  pure  waltzing. 

OCCURRENCE  OF  MENDELIAN  INHERITANCE. — 
Mendelian  phenomena  are  known  in  rats,  mice, 
rabbits,  guinea-pigs,  poultry,  canaries,  snails,  silk- 
worms, and  some  other  animals ;  in  peas,  beans, 
stocks,  wheat,  barley,  maize,  and  some  other 
plants.  The  characters  which  illustrate  it  are 
such  as  size,  colour,  markings,  crests,  horns,  hairi- 
ness, peculiar  features  such  as  the  waltzing  habit 
in  mice,  and  elusive  properties,  such  as  broodiness 
in  hens,  time  of  ripening  and  immunity  in  wheat. 

It  is  doubtful  how  far  Mendelian  phenomena 


FACTS    OF    INHERITANCE  155 

occur  in  man.  Human  eyes  may  be  arranged  in 
two  groups :  (a)  those  with  brown  pigment  on  the 
outer  as  well  as  on  the  inner  surface  of  the  iris 
(usually  browns  and  greens) ;  and  (6)  those  without 
such  brown  pigment  on  the  outer  side,  but  with 
some  pigment  on  the  inner  side  (blues  and  greys). 
It  appears,  from  the  researches  of  Hurst  and  of 
Prof,  and  Mrs.  Davenport,  that  the  first  type  is 
dominant  and  the  second  recessive.  Hurst  also 
gives  some  evidence  that  "  fiery  red  "  hair  behaves 
as  a  recessive  to  brown,  and  that  the  musical  sense 
is  recessive  to  the  non-musical.  The  clearest  case, 
as  yet,  is  that  peculiar  condition  of  the  hands  and 
feet  known  as  brachydactyly,  which  Farabee  and 
Drinkwater  have  found  to  be  dominant  to  the 
normal  condition.  Of  great  interest  also  is  Mr. 
Nettleship's  account  of  the  descendants  of  one 
Jean  Nougaret  (born  1637)  who  was  afflicted  with 
night  blindness — a  condition  apparently  due  to  loss 
of  the  visual  purple.  There  are  records  of  over 
2,000  individuals ;  and  the  night  blindness  is 
dominant  over  the  normal.  During  two  and  a  half 
centuries  no  normal  member  of  the  family  who 
has  married  another  normal,  whether  related  or 
not,  has  ever  transmitted  the  disease. 

PRACTICAL  IMPORTANCE  OF  MENDELISM. — The 
work  of  the  Mendelian  school  of  experimenters 
since  1900  is  full  of  achievement  and  promise,  and 
no  naturalist  can  help  envying  those  who  have  been 
able  to  share  in  it,  all  the  more  that  their  dis- 
coveries are  full  of  practical  as  well  as  theoretical 
import.  Prof.  Bateson  writes  :  "  If  we  want  to 
raise  mangels  that  will  not  run  to  seed,  or  to  breed 
a  cow  that  will  give  more  milk  in  less  time,  or  milk 
with  more  butter  and  less  water,  we  can  turn  to 


156       DARWINISM   AND    HUMAN    LIFE 

genetics  with  every  hope  that  something  can  be 
done  in  these  laudable  directions.  But  here  I 
would  plead  what  I  cannot  but  regard  as  a  higher 
usefulness  in  our  work.  Genetic  inquiry  aims  at 
providing  knowledge  that  may  bring,  and  I  think 
will  bring,  certainty  into  a  region  of  human  affairs 
and  concepts  which  might  have  been  supposed  re- 
served for  ages  to  be  the  domain  of  the  visionary." 
He  alludes  to  liability  to  particular  disease,  addic- 
tion to  a  particular  vice,  and  so  on,  and  says :  "  As 
regards  the  more  tangible  of  these  physical  and 
mental  characteristics  there  can  be  little  doubt 
that,  before  many  years  have  passed,  the  laws  of 
their  transmission  will  be  expressible  in  simple 
formulae/' * 

MUCH  PEOGRESS,  BUT  GREAT  UNCERTAINTY. — 
Especially  through  the  work  of  the  Mendelians 
great  strides  have  been  made  in  the  last  ten  years 
in  our  knowledge  of  the  laws  of  inheritance.  By 
breeding  two  pairs  of  rabbits  which,  to  the  ordinary 
eye,  seem  identical,  an  experimenter  like  Mr.  Hurst 
acquires  a  knowledge  of  their  inherent  germinal 
qualities  (or  gametic  constitution),  and  he  can 
successfully  predict  the  difference  between  the 
results  of  mating  the  two  pairs.  The  statisticians 
can  predict  average  results  in  1,000  offspring  ;  the 
Mendelian  breeder  can  predict  the  distribution  of 
certain  characters  in  a  litter.  In  spite  of  this 
progress,  and  partly  because  of  it,  we  are  confronted 
with  an  array  of  unanswered  questions  concerning 
this  most  fascinating  of  problems.  In  what  cases 
are  the  facts  of  inheritance  clearly  Mendelian, 
and  how  do  these  cases  differ  from  others  that 
seem  as  clearly  non-Mendelian  ?  Is  it  the  case 

1  W.  Bateson,  "  The  Methods  and  Scope  of  Genetics  "  (1908). 


FACTS    OF   INHERITANCE  157 

that  particular  ancestral  qualities  may  be  latent 
for  more  than  two  generations,  and  then  re-assert 
themselves  as  reversions  ?  What  adjustment  of 
statement,  if  any,  will  bring  Galton's  Law  (a 
statistical  conclusion)  and  Mendel's  Law  (an 
experimental  conclusion)  into  harmony  ?  What  is 
the  nature  of  the  character  which  we  call  "  male- 
ness  "  or  "  femaleness,"  and  is  there  any  law 
which  will  formulate  its  distribution  in  the  progeny 
of  a  pair  ?  These  are  some  of  the  urgent  questions 
towards  the  answering  of  which  facts  are  accumu- 
lating every  month. 

THE  TRANSMISSION  OF  ACQUIRED  CHARACTERS. — 
Let  us  turn,  however,  for  a  little  to  the  long-drawn- 
out  controversy  as  to  the  possible  transmission  of 
"  acquired  characters,"  or  somatic  modifications. 
It  may  be  said  that  the  disputants  are  now  agreed 
as  to  the  precise  point  at  issue,  and  perhaps  it 
may  also  be  said  that  neither  the  yeas  nor  the  nays 
ring  out  so  confidently  as  they  did  ten  years  ago.. 
Let  us  state  the  case.  Members  of  the  same  species 
often  differ  from  one  another,  and  these  differences 
can  be  measured  and  registered  under  the  title  of 
"  observed  differences,"  which  commits  one  to  no 
theory.  Many  of  these  differences  depend  on  age 
and  sex,  and  these  can  be  readily  recognised  and 
allowed  for.  Others  depend  on  peculiarities  of 
"  nurture,"  in  the  wide  sense ;  that  is,  they  are 
the  direct  results  of  peculiarities  in  surrounding 
influences  or  in  function.  Such  changes  in  plant 
or  animal  are  impressed  from  without,  they  are 
"  exogenous "  in  origin,  they  are  acquired  not 
inborn,  and  they  are  technically  called  "  somatic 
modifications,"  or  "  acquired  characters."  They 
may  be  defined  as  structural  changes  in  the  body  of 


158       DARWINISM   AND   HUMAN    LIFE 

an  individual  directly  induced  by  changes  in  junction 
or  in  environment,  which  transcend  the  limit  of 
organic  elasticity  and  thus  persist  after  the  inducing 
conditions  have  ceased  to  operate.  Thus  fattening 
and  sunburning  are  modifications,  though  the 
predisposition  to  them  may  be  inborn  ;  the  forma- 
tion of  a  callosity  as  the  result  of  pressure  and 
the  reduction  of  a  muscle  by  prolonged  disuse  are 
modifications,  though  it  does  not,  of  course,  follow 
that  callosities  and  reduced  muscles  may  not  come 
about  in  a  quite  different  way,  namely,  by  a  germinal 
variation.  Now,  when  we  subtract  from  the  total 
of  observed  differences  between  members  of  the 
same  species  all  that  can  be  described  as  modifica- 
tions, we  find  a  large  remainder  which  we  must 
define  off  as  inborn  or  germinal  variations.  We 
cannot  causally  relate  them  to  any  peculiarities 
in  the  organism's  habits  or  surroundings,  they  are 
often  distinct  at  birth  or  hinted  at  before  birth, 
they  are  rarely  alike  even  among  forms  whose 
conditions  of  life  seem  absolutely  uniform.  They 
are  endogenous,  not  exogenous  in  origin  ;  they  are 
results  of  changes  in  the  germinal  material ;  they 
are  born,  not  made ;  and  they  are  more  or  less  trans- 
missible, though  they  are  not  by  any  means  always 
transmitted.1  They  form — at  least  some  of  them 
form — the  raw  material  of  organic  evolution, 
whereas  modifications,  as  defined,  are  probably  not 
of  direct  importance  in  evolution,  since  we  have  no 
secure  evidence  that  they  are  ever  transmitted  as 
such,  or  in  any  representative  degree. 

1  Darwin  assumed  that  little  fluctuations  are  more  certainly 
transmissible  than  marked  idiosyncrasies,  but  all  that  we  are  quite 
certain  of  is  that  a  number  of  variations,  both  large  and  small,  are 
definitely  transmissible. 


FACTS    OF   INHERITANCE  159 

There  is  no  doubt  that  modifications  are  very 
common,  that  they  are  of  much  individual  import- 
ance, that  they  may  have  an  indirect  influence 
through  the  body  on  the  offspring  (especially  in 
the  case  of  mammalian  mothers),  that  they  may 
have  an  indirect  importance  in  evolution  in  several 
ways,  but  the  precise  point  at  issue  is  this  :  Does 
a  structural  change  in  a  part  of  the  body,  induced  by 
use  or  disuse,  or  by  change  in  surroundings  and 
nurture  generally,  ever  influence  the  germ-plasm  in 
the  reproductive  organs  in  such  a  specific  or  re- 
presentative way  that  the  offspring  will  thereby 
exhibit  the  same  modification  that  the  parent  ac- 
quired, or  even  a  tendency  towards  it  ?  We  do  not 
know  of  any  clear  case  which  would  at  present 
/warrant  the  assertion  that  a  somatic  modification 
!  is  ever  transmitted  from  parent  to  offspring. 

In  regard  to  this  important  question,  let  us  try  to 
clear  the  ground  by  noting  a  few  of  the  common 
misunderstandings.1 

I.  How  can  there  be  progressive  evolution  if 
acquired   characters   are  not  entailed  ?     By  the 
accumulation  of  germinal  variations,  such  as  those 
which  have  separated  the  higher  from  the  lower 
races  of  mankind.     Yet  Herbert  Spencer  actually 
said,  "  Either  there  has  been  inheritance  of  acquired 
characters,  or  there  has  been  no  evolution."    In 
1796  the  speed  of  the  English  trotter  was  a  mile 
in  2  mins.  37  sees.  ;    it  is  now  a  mile  in  2  mins. 
10  sees.,  or  less ;   but  that  is  the  result  of  the 
selection  of  inborn  variations,  not  of  the  trans- 
mission of  acquired  characters. 

II.  Many  facts  in  nature  are  readily  interpretable 

1  See  "  Heredity,"  by  J.  Arthur  Thomson.  (Murray.  London 
1908.) 


160       DARWINISM   AND    HUMAN    LIFE 

on  the  theory  that  the  results  of  use  and  disuse  and 
of  environmental  change  are,  as  such,  transmissible. 
The  black  skin  may  be  interpreted  as  due  to  the 
sun.  The  callosities  on  the  knees  of  the  wart-hog 
may  be  interpreted  as  due  to  pressure  on  the  ground. 
The  twelve  hours'  sleeping  and  waking  of  many 
acacias  may  be  interpreted  as  a  functional  adap- 
tation which  has  become  hereditary.  But  the 
interpretations  may  be  erroneous. 

III.  Many  beg  the  question  by  starting  with  a 
character,   like  short-sightedness  or  gout,   which 
has  not  been  proved  to  be  a  modification.    First 
catch  your  modification.     The  little  toe  is  said  to 
be  dwindling  in  consequence  of  wearing  tight  boots ; 
but  we  are  not  sure  that  there  is  dwindling,  and  if 
there  is,  we  have  no  experimental  reason  for  blaming 
the  boots. 

IV.  The  reappearance  of  a  modification  in  suc- 
cessive generations  is  often  mistaken  for  trans- 
mission.    It  may  be  hammered  on  to  each  suc- 
cessive generation.     Nageli  put  Alpine  plants  in 
rich  garden  soil  and  they  became  very  different, 
and  their  progeny  likewise ;    but  transference  to 
poor  soil  brought  back  the  Alpine  characters,  which 
showed  that  the  new  characters  had  not  taken 
any  hereditary  grip. 

V.  Infection  of  the  offspring  by  the  parent  before 
birth  has  nothing  to  do  with  inheritance  in  the 
true  sense. 

VI.  Transmission  in  unicellular  organisms  is  not 
to  the  point,  for,  as  they  have  no  "  body,"  the 
concept  of  somatic  modifications  does  not  apply  to 
them. 

VII.  Changes    in    the    germ-cells    along    with 
changes   in   the   body,    where    there    are   deeply 


FACTS   OP   INHERITANCE  161 

saturating   influences   such   as   poisons,    are   not 
cogent. 

VIII.  Modifications  may  have  secondary  effects 
on  the  germ-cells  and  the  offspring,  e.g.  in  the  way 
of  bad  nutrition,  but  unless  the  offspring  show 
peculiarities  in  the  same  direction  as  the  original 
modifications,  we  have  no  data  bearing  precisely 
on  the  question  at  issue. 

A  belief  in  the  inheritance  of  modifications  was 
perhaps  expressed  in  the  old  proverb,  "  The  fathers 
have  eaten  sour  grapes,  and  the  children's  teeth 
are  set  on  edge  " — a  proverb  which  Ezekiel,  with 
such  solemnity,  said  was  not  any  more  to  be  used 
in  Israel.  Now  if  "  setting  on  edge "  was  a 
structural  modification,  and  if  the  children's  teeth 
were  "  set  on  edge  "  as  their  fathers'  had  been 
before  them,  there  would  be  a  presumption  in 
favour  of  the  transmission  of  this  acquired  char- 
acter, though  it  would  be  still  necessary  to  inquire 
carefully  whether  the  children  had  not  been  in  the 
vineyard  too.  If,  as  Romanes  said,  the  children 
were  born  with  wry  necks,  we  should  have  to  deal 
with  the  inheritance  of  an  indirect  result  of  the 
parents'  vagaries  of  appetite,  and  not  with  any 
direct  representation  in  inheritance  of  the  particu- 
lar modification  produced  in  the  paternal  dentition. 

IX.  Finally,  there  is  no  use  appealing  to  data 
from  fewer  than  three  generations.    Sheep  trans- 
ported to  a  cold  country  get  longer  fleece,  their 
offspring  have  still  longer  fleece;  but  this  is  not 
to  the  point,  since  the  offspring  were  subjected  to 
the  modifying  influences  from  birth.      We  wish 
to  know  whether  the  third  generation  is  more 
markedly  modified  than  the  second. 

DISEASE. — As  a  particular  case  we  may  take 

11 


162       DARWINISM  AND   HUMAN   LIFE 

the  important  question  of  the  transmissibility  of 
acquired  disease.  When  the  question  is  carefully 
considered,  it  seems  possible  to  distinguish  be- 
tween (1)  abnormal  or  deranged  processes  which 
have  their  roots  in  germinal  peculiarities  or  de- 
fects (variations),  and  (2)  abnormal  or  deranged 
processes  which  have  been  directly  induced 
in  the  body  by  acquired  modifications,  i.e.  as 
the  results  of  unnatural  surroundings  or  habits, 
including  the  intrusion  of  parasites.  There  is 
very  little  evidence  to  suggest  that  this  second 
kind  of  disease  is  heritable  as  such,  though  the 
indirect  effects  may  influence  the  offspring.  When 
we  go  further  and  come  to  understand  that  pre- 
natal infection  is  not  inheritance,  that  inheritance 
of  a  predisposition  to  a  disease  is  not  inheritance 
of  the  disease,  that  the  general  weakening  of  the 
offspring  through  disease  in  the  parent  is  a  very 
different  matter  from  the  transmission  of  a  specific 
disease,  we  are  almost  irresistibly  led  to  the  con- 
clusion that  in  the  sense  in  which  the  word  "  in- 
herited "  is  used  in  biology,  there  are  no  inherited 
diseases.  What  does  seem  to  be  inherited,  how- 
ever, is  a  defectiveness  or  degeneracy  of  the  germ- 
plasm  which  finds  one  expression  in  the  parent  and 
another  in  the  offspring. 

FACTS  AND  POSSIBILITIES. — The  evidence  in 
support  of  the  transmission  of  acquired  characters 
is  either  very  anecdotal  or  very  uncritical,  and, 
until  some  cogent  cases  are  forthcoming,  the 
thoroughgoing  scepticism  which  Weismann  ex- 
pressed many  years  ago  remains  justified. 

Besides  the  unsatisfactory  nature  of  the  evidence, 
we  have  to  admit  the  difficulty  of  imagining  any 
means  whereby  a  modification  of  a  particular 


PACTS   OF   INHERITANCE  163 

organ  of  the  body  can  react  upon  the  germ-cells  in 
a  manner  so  specific  that  these  can,  when  they 
develop,  reproduce  the  particular  parental  modifi- 
cation or  any  approach  to  it.  Darwin  and  Spencer 
both  faced  this  difficulty,  and  tried  to  meet  it ;  but 
no  one  now  accepts  their  provisional  hypotheses. 
It  is  true  that  a  mechanism  may  exist  though  it 
remains  unknown ;  it  is  true  that  important  in- 
fluences, mysterious  in  their  nexus,  pass  from 
reproductive  organs  to  body;  but  we  should  not 
have  recourse  to  difficult  hypotheses  before  we 
are  sure  that  there  is  any  need  for  them.  There 
is  no  doubt  that  the  germ-plasm  may  be  influ- 
enced by  the  blood,  but  this  is  different  from 
admitting  the  transmission  of  a  particular  acquired 
character. 

In  a  well-known  case,  where  the  evidence  points, 
according  to  some,  to  the  heritability  of  an  arti- 
ficially induced  epileptic  condition,  it  has  been 
suggested  that  the  epilepsy  produces  a  toxin  which 
passes  to  the  germ-cells  so  that  the  offspring  are 
epileptically  affected.  Now  if  we  dared  to  suppose 
that  a  deeply  saturating  modification  produces  a 
representative  chemical  substance  analogous  to  a 
toxin,  and  that  this  passes  to  the  germ-cells,  the 
hereditary  reappearance  of  a  modification  would 
be  more  conceivable. 

There  are  many  who  think  that,  sooner  or  later, 
there  must  be  a  return  to  Darwin's  idea  of  pan- 
genesis — of  specific  substances  passing  from  body 
to  germ-cells.  The  study  of  hormones  is  a  line  of 
investigation  that  is  of  much  interest  in  this  con- 
nection. "  Hormones "  are  specific  substances 
produced  by  cells,  and  passed  into  the  blood- 
stream to  play  an  important  part  in  stimulating 


164       DARWINISM   AND    HUMAN   LIFE 

or  controlling  developmental  and  metabolic  pro- 
cesses. Injection  of  extracts  of  thyroid  has  usually 
a  beneficial  effect  in  reducing  goitre.  Injection  of 
extracts  of  foetus  has  an  effect  on  the  mammary 
glands.  Injection  of  testicular  extract  causes  the 
temporary  development  of  a  cock's  comb  on  a  hen. 
There  are  enough  of  facts  of  this  kind  to  make  us 
chary  of  dogmatism  in  regard  to  the  possibility  of 
an  influence  passing  from  a  modification  of  the 
body  to  the  germ-cells  thereof.  As  Prof.  E.  B. 
Wilson  says  :  "  Let  us  admit  freely  that  such  an 
interaction  as  Darwin  assumed  may  be  a  real  and 
potent  factor  in  heredity,  though  it  gives  us  no 
hint  of  its  existence  in  the  visible  apparatus  of 
the  cell.  In  the  present  defective  state  of  our 
knowledge  we  may  well  grant  that  there  may 
be  many  a  thing  between  germ-cell  and  body 
that  is  not  yet  dreamed  of  in  our  biological 
philosophy."  l 

A  STRIKING  CASE. — Kammerer's  experiments  on 
salamanders  afford  the  most  remarkable  piece  of 
evidence  as  yet  adduced  in  support  of  the  thesis 
that  acquired  characters  may  be  transmitted. 

(a)  The  common  yellow  and  black-spotted 
salamander  (Salamandra  maculosa)  is  either  vivi- 
parous, producing  a  large  number  of  larvae 
25-30  mm.  in  length  with  four  limbs  and  short 
gills,  or  ovo-viviparous,  laying  large  eggs  which 
hatch  out  into  similar  larvae  23-25  mm.  in  length. 
After  a  few  months  of  larval  life  in  the  water, 
they  undergo  metamorphosis  into  land-salamanders 
45-56  mm.  in  length. 

(6)  The  black  Alpine  Salamander  (Salamandra 

1  "  The  Cell  in  Relation  to  Heredity  and  Evolution,"  in  "  Fifty 
Years  of  Darwinism"  (1909),  p.  113. 


FACTS    OF   INHERITANCE  165 

atra)  produces  at  birth  two  fully  formed  terrestrial 
young  38-40  mm.  in  length. 

(c)  Kammerer  kept    S.  maculosa  in  the  cold, 
and  got  it,  after  a  few  pregnancies,  to  produce  only 
two  young  ones,  as  in  S.  atra. 

(d)  He  kept  S.  atra  in  a  warm  place  with  plenty 
of  water,  and  got  it  to  produce  3-9  aquatic  larvae, 
thus  approaching  the  condition  in  S.  maculosa. 

(e)  The    offspring    of     the    Salamanders    thus 
treated  (c  and  d),  became  sexually  mature  when 
three  and  a  half  years  old  in  conditions  normal 
to  S.  maculosa.     The  offspring  of  (c)  gave  birth 
(1)  to  very  advanced  larvae,  45  mm.  long  with 
much-reduced  gills,  metamorphosing  several  days 
after,    or    moderately    advanced    aquatic    larvae 
40  mm.  long,  with  large  gills ;    or  (2)  to  small 
larvae,  20  mm.  long,  with  rudimentary  gills,  laid 
on  land,  and  metamorphosing  after  four  weeks 
into  salamanders  29  mm.  long.     Thus  there  was 
a  partial  persistence  of  a  modified  mode  of  re- 
production   in    the    absence    of    the    modifying 
conditions. 

(/)  The  offspring  of  (d)  bore  in  the  water  3-5 
larvae,  33-40  mm.  or  21-23  mm.  in  length,  light 
in  colour,  and  possessing  gills.  Thus  there  was 
an  augmentation  of  the  parental  modification 
(d)  in  conditions  which  resembled  those  of  the 
original  experiment. 

The  difficulties  in  regard  to  this  very  interesting 
set  of  experiments  are :  (1)  they  do  not  deal 
with  a  structural  modification ;  (2)  it  is  possible 
that  the  experimental  conditions  acted  directly 
on  the  germ-cells  in  (c)  and  (d) ;  (3)  there  was 
some  measure  of  artificiality  in  the  conditions 
under  which  the  second  generation  developed, 


166       DARWINISM   AND   HUMAN    LIFE 

which  may  have  disturbed  the  normal  routine  of 
reproduction. 

LOGICAL  POSITION  OF  THE  QUESTION. — Let  us 
notice  the  logical  position  of  the  question.  There 
are  two  possible  lines  of  argument :  (a)  by  experi- 
ment, and  (6)  by  interpretation,  (a)  As  to  ex- 
periment, it  is  plain  that  hundreds  of  failures 
to  prove  the  transmission  do  not  demonstrate 
its  impossibility.  They  only  show  that  it  is 
not  usual.  One  good  case  experimentally  proved 
would  show  that  the  transmission  is  possible. 
The  best  case  we  know  is  Kammerer's,  and  it 
does  not  seem  cogent.  Perhaps  better  cases  will 
become  known.  The  Lamarckian  does  not,  of 
course,  say  that  every  change  of  conditions  will 
produce  appreciable  hereditary  effects  in  a  few 
generations,  or  that  any  particular  change  of 
conditions  chosen  more  or  less  arbitrarily  for 
experimental  purposes  will  produce  recognisable 
results  in  the  following  generation.  But  do  we 
know  of  any  clear  case  of  even  a  faint  trace  of  a 
well-defined  structural  modification  being  trans- 
mitted ?  (b)  As  to  the  second  method,  that  of 
the  interpretation  of  facts,  it  cannot  be  conclusive 
either,  since  each  side  has  to  prove  a  negative  in 
order  to  establish  its  case.  The  Neo-Lamarckians 
have  to  show  that  the  phenomena  they  adduce 
as  illustrations  of  modification-inheritance  cannot 
be  interpreted  as  the  results  of  selection  operating 
on  germinal  variations.  In  order  to  do  this  to 
the  satisfaction  of  the  other  side,  the  Neo-Lamarck- 
ians must  prove  that  the  characters  in  question 
are  outside  the  scope  of  natural  selection,  that 
they  are  non-utilitarian  and  not  correlated  with 
any  useful  characters — a  manifestly  difficult  task, 


FACTS   OF   INHERITANCE  167 

The  Neo-Darwinians,  on  the  other  hand,  have  to 
prove  that  the  phenomena  in  question  cannot 
be  the  results  of  modification-inheritance.  And 
this  is,  in  most  cases,  impossible.  Thus  we  seem 
to  reach  a  logical  dead-lock.  What  we  need  are 
more  facts. 

CASES  WHERE  THE  THEORY  OF  MODIFICATION- 
INHERITANCE  is  INAPPLICABLE. — It  is  true,  how- 
ever, that  there  are  certain  characters  of  particular 
organisms  in  regard  to  which  it  may  be  said  with 
some  security  that  they  could  not  have  arisen  by 
the  inheritance  of  acquired  modifications.  Thus 
many  insects,  and  the  like,  have  adaptive  characters 
in  their  cuticular  structures — knobs  for  crushing, 
saws  suited  for  cutting,  gimlets  suited  for  boring, 
and  so  on.  But  these  cuticular  structures  are 
non-cellular,  non-living  parts  of  the  external 
investment  of  the  body ;  they  are  made  and 
remade  (after  moulting)  by  the  underlying,  living 
skin.  How,  then,  can  they  be  interpreted  in 
terms  of  modification-inheritance  ?  The  matter 
becomes  even  more  difficult  when  we  consider 
cases  in  which  the  adaptiveness  is  in  the  colour 
or  markings  of  these  inert  cuticular  parts.  Weis- 
mann  has  argued  that,  since  there  are  some  adaptive 
characters  which  cannot  be  interpreted  in  terms 
of  modification-inheritance,  this  hypothetical  factor 
need  not  be  assumed  in  attempting  to  interpret 
the  origin  of  other  adaptations,  similar  to  the 
former,  except  that  the  factor  in  question  is  not 
by  the  nature  of  the  case  apparently  excluded 
from  having  any  connection  with  them. 

But  it  cannot  be  said  that  this  application  of 
the  "  law  of  parsimony  "  is  altogether  successful. 
It  may  recoil  on  those  who  use  it,  It  might  be 


168       DARWINISM   AND    HUMAN   LIFE 

argued  that  there  are  some  adaptive  characters 
which  cannot  be  readily  interpreted  in  terms 
of  natural  selection  (as  is  implied  in  the  appeal 
of  some  Neo-Darwinians  to  "  intra-selection," 
"  germinal  selection,"  and  so  on),  and  that  therefore 
natural  selection  cannot  be  regarded  as  a  generally 
acting  factor.  Moreover,  the  Neo-Lamarckian  is 
at  liberty  to  reply  that  he  does  not  regard  the 
modification-inheritance  theory  as  applicable  to 
all  possible  cases. 

IMPORTANCE  OF  ENVIRONMENT  AND  FUNCTION 
REMAINS. — Although  bodily  changes  due  to 
changes  in  environment  or  in  function  may  not 
be  transmissible,  the  importance  of  these  influences 
remains.  (1)  An  inheritance  cannot  be  realised 
without  an  environment,  any  more  than  a  man 
whose  legacy  was  a  cheque  could  make  much  of 
it  without  a  bank.  (2)  Changes  in  environment 
and  function,  saturating  through  the  body,  may 
stimulate  the  variability  of  the  germ-plasm.  This 
may  be  the  cause  of  mutation.  (3)  Living  creatures 
are  in  many  cases  very  plastic,  and  their  modifica- 
tions are  often  of  great  individual  importance, 
and  may  even  preserve  the  life.  (4)  The  secondary 
effects  of  modifications  may  reach  and  influence 
the  germ-cells.  (5)  Every  one  admits  that  the 
state  of  the  maternal  constitution  is  very  important 
in  all  cases  where  there  is  an  intimate  connection 
between  the  mother  and  the  unborn  young. 

SELECTION  AND  STIMULUS. — In  two  other  ways 
changes  in  the  conditions  of  life  are  of  great  im- 
portance :  they  form  part  of  the  mechanism  of 
selection,  whereby  the  relatively  less  fit  variants 
are  quickly  or  slowly,  roughly  or  gently,  eliminated, 
and  they  act  as  a  stimulus  to  the  intrinsic  self- 


FACTS    OF   INHERITANCE  169 

assertiveness  and  "  endeavour  after  well-being  " 
which  characterise  living  creatures.  We  must 
advance  beyond  the  conventional  view  that  the 
environment  is  like  a  net  closing  in  upon  passive 
victims,  which  can  only  escape  if  they  have  been 
fitted  by  germinal  variation  (or  acquired  modifica- 
tion) to  pass  through  some  of  the  meshes ;  we 
must  recognise,  as  a  fact  of  life,  what  Lamarck 
and  many  others  have  discerned,  that  organisms 
actively  assert  themselves  against  this  closing 
net,  and  by  active  endeavour  (also,  of  course,  a 
variational  character  when  traced  back)  may 
win  their  way  through.  At  certain  levels  every 
one  is  actively  on  the  outlook  for  "  a  niche  of 
organic  opportunity."  In  his  "  Luck  or  Cunning  ?  " 
Mr.  Samuel  Butler  asked,  "  Do  animals  and  plants 
grow  into  conformity  with  their  surroundings 
because  they  and  their  fathers  take  pains,  or 
because  their  uncles  and  aunts  go  away  ?  "  The 
accurate  answer  is  that  the  question  is  wrongly 
put,  for  even  those  who  most  believe  in  the 
negative  importance  of  uncles  and  aunts  going 
away  will  be  willing  to  admit,  likewise,  the  positive 
importance  of  "  taking  pains/'  A  rehabilitation 
of  the  Lamarckian  position  perhaps  depends  on 
making  clear  what  the  "  effort "  of  the  creature 
amounts  to,  and  what  it  really  means. 

INDIRECT  IMPORTANCE  OF  MODIFICATIONS. — 
But  there  is  another  important  consideration, 
which  has  been  stated  independently  by  Profs. 
Mark  Baldwin,  Lloyd  Morgan,  and  H.  F.  Osborn, 
namely,  that  adaptive  modifications  may  act  as 
the  fostering  nurses  of  germinal  variations  in  the 
same  direction.  We  have  referred  to  this  else- 
where, but  it  may  give  greater  completeness  to 


170       DARWINISM   AND   HUMAN   LIFE 

our  survey  if  we  quote  a  brief  statement  of  the 
idea  as  expounded  by  Lloyd  Morgan  ("  Habit 
and  Instinct"  (1896),  p.  319) : 

"  Persistent  modification  through  many  genera- 
tions, though  not  transmitted  to  the  germ,  neverthe- 
less affords  the  opportunity  for  germinal  variation 
of  like  nature. 

"  Suppose  that  a  group  of  plastic  organisms  is 
placed  under  new  conditions.  Those  whose  innate 
plasticity  is  equal  to  the  occasion  are  modified 
and  survive.  Those  whose  plasticity  is  not  equal 
to  the  occasion  are  eliminated.  .  .  .  Such  modifica- 
tion takes  place  generation  after  generation,  but, 
as  such,  is  not  inherited.  .  .  .  But  any  congenital 
variations  similar  in  direction  to  these  modifications 
will  tend  to  support  them  and  to  favour  the 
organism  in  which  they  occur.  Thus  will  arise 
a  congenital  predisposition  to  the  modifications 
in  question. 

"  The  plasticity  still  continuing,  the  modifica- 
tions become  yet  further  adaptive.  Thus  plastic 
modification  leads,  and  germinal  variation  follows  ; 
the  one  paves  the  way  for  the  other. 

"  The  modification,  as  such,  is  not  inherited, 
but  is  the  condition  under  which  congenital 
variations  are  favoured  and  given  time  to  get  a 
hold  on  the  organism,  and  are  thus  enabled  by 
degrees  to  reach  the  fully  adaptive  level." 

PRACTICAL  IMPORT  OF  THE  QUESTION  AS  TO  THE 
TRANSMISSIBILITY  OF  ACQUIRED  CHARACTERS. — 
It  is  scarcely  necessary  to  point  out  that  the  long- 
drawn-out  discussion  is  one  of  great  importance, 
affecting  our  whole  theory  of  evolution,  and  even 
our  everyday  conduct.  Herbert  Spencer  went 
the  length  of  saying  that  "  a  right  answer  to  the 


FACTS    OF   INHERITANCE  171 

question,  whether  acquired  characters  are  or  are 
not  transmitted,  underlies  right  beliefs,  not  only 
in  biology  and  psychology,  but  also  in  education, 
ethics,  and  politics." 

A  modification  is  a  definite  change  in  the 
individual  body,  due  to  some  change  in  "  nurture." 
There  is  no  secure  evidence  that  any  such  individual 
gain  or  loss  can  be  transmitted  as  such,  or  in  any 
representative  degree.  How  does  this  affect  our 
estimate  of  the  value  of  "  nurture  "  ?  How  should 
the  sceptical  or  negative  answer,  which  we  believe 
to  be  the  scientific  one,  affect  our  practice  in  regard 
to  education,  physical  culture,  amelioration  of 
function,  improvement  of  environment,  and  so  on  ? 

(a)  Every  inheritance  requires  an  appropriate 
nurture  if  it  is  to  realise  itself  in  development. 
Nurture  supplies  the  liberating  stimuli  necessary 
for  the  full  expression  of  the  inheritance.  A 
man's  character  as  well  as  his  physique  is  a  function 
of  "  nature  "  and  of  "  nurture."  In  the  language 
of  the  old  Parable  of  the  Talents,  what  is  given 
must  be  traded  with.  A  boy  may  be  truly  enough 
a  chip  of  the  old  block,  but  how  far  he  shows  him- 
self such  depends  on  "  nurture."  The  conditions 
of  nurture  determine  whether  the  expression  of 
the  inheritance  is  to  be  full  or  partial.  It  need 
hardly  be  said  that  the  strength  of  an  (inherited) 
individuality  may  be  such  that  it  expresses  itself 
almost  in  the  face  of  inappropriate  nurture.  History 
abounds  in  instances.  As  Goethe  said,  man  is 
always  achieving  the  impossible.  Semon  relates 
a  pretty  experiment  with  young  acacias  (Albizzia 
lophantha).  They  had  never  been  exposed  to  the 
normal  alternation  of  day  and  night,  to  which 
their  race  responds  by  expanding  and  closing  the 


172       DARWINISM  AND  HUMAN   LIFE 

leaves.  Semon  exposed  them  to  artificial  days  and 
nights  of  six  horns'  or  twenty-four  hours'  duration  ; 
bnt  the  plants  exhibited  the  twelve-hours'  cycle 
quite  miTnisia.lra.h1y  —  just  a  little  altered.  After 
this  experiment  Semon  exposed  the  plants  to 
continuous  darkness  or  continuous  illumination. 
The  twelve-hours'  cycle  stifl  manifested  itself  for 
a  time,  but  gradually  became  indistinct.  Here 
we  see  the  inherited  nature  struggling,  as  it  were, 
against  inappropriate  nurture. 

(6)  Although  modifications  do  not  seem  to  be 
transmitted  as  such,  or  in  any  representative  degree, 
there  is  no  doubt  that  they  or  their  secondary 
results  may  in  some  cases  affect  the  offspring. 
This  is  especially  the  case  in  typical 


where  there  is  before  birth  a  prolonged  (placental) 
connection  between  the  mother  and  the  unborn 
young.  In  such  cases  the  offspring  is  for  a  time 
almost  part  of  the  maternal  body,  and  liable  to  be 
affected  by  modifications  thereof  —  e.g.  by  good 
or  bad  nutritive  conditions.  In  other  cases,  also, 
it  may  be  that  deeply  saturating  parental  modifica- 
tions, such  as  the  results  of  alcoholic  and  other 
poisoning,  affect  the  germ-cells,  and  thus  the 
offspring.  A  disease  may  saturate  the  body  with 
toxins  and  waste-products,  and  these  may  provoke 
prejudicial  germinal  variations. 

(c)  Though  modifications  due  to  changed 
"  nurture  "  do  not  seem  to  be  transmissible,  they 
may  be  reimpressed  on  each  generation.  Thus 
"  nurture  "  becomes  not  less,  but  more,  important 
in  our  eyes.  "  Is  my  grandfather's  environment 
not  my  heredity  ?  "  asks  an  American  author 
quaintly  and  pathetically.  Well,  if  not,  let  us 
secure  for  ourselves  and  for  our  children  those 


FACTS   OF  INHERITANCE  173 

factors  in  the  "  grandfather's  environment "  that 
made  for  progressive  evolution,  and  eschew  those 
that  tended  elsewhere. 

Are  modifications  due  to  changed  nurture  not 
entailed  on  offspring  ?  Perhaps  it  is  just  as  well, 
for  we  are  novices  at  nurturing  even  yet.  More- 
over, the  non-transmissibility  cuts  both  ways :  if 
individual  modificational  gains  are  not  handed  on, 
neither  are  the  losses. 

Is  the  "  nature  " — the  germinal  constitution,  to 
wit,  all  that  passes  from  generation  to  generation — 
the  capital  sum  without  the  results  of  individual 
usury  ?  Then  we  are  freed,  at  least,  from  undue 
pessimism,  because  of  the  many  harmful  functions 
and  environments  that  disfigure  our  civilisation. 
Many  detrimental  acquired  characters  are  to  be 
seen  all  around  us,  but  if  they  are  not  transmissible, 
they  need  not  last. 

(d)  The  plasticity  of  the  organism  admits  of 
definite  modifications  being  reimpressed  on  succes- 
sive generations  of  individuals,  and  this  is  the  more 
important  when  we  consider  what  has  been  said 
in  the  section  on    "The  Indirect  Importance  of 
Modifications."    They  may  serve  as  modificational 
screens  until  coincident  variations  in  the  same 
direction  can  emerge  and  establish  themselves. 
This  also  cuts  both  ways  in  human  societies,  where 
natural  selection  is  interfered  with,  and  where 
naturally  prejudicial  deviations  from  the  norm  are 
not  necessarily  punished  by  elimination. 

(e)  Of  particular  importance  is  the  fact  that 
man,  in  contrast  to  other  creatures,  has  developed 
around  him  an  external  heritage,  a  social  framework 
of  customs  and  traditions,  of  laws  and  institutions, 
of  literature  and  art,  by  which   results  almost 


174       DARWINISM   AND    HUMAN   LIFE 

equivalent  to  the  organic  transmission  of  certain 
kinds  of  modifications  may  be  brought  about. 

(/)  Is  there  not  some  result  of  the  almost  tire- 
some controversy  on  "  the  inheritance  of  acquired 
characters/'  if  we  are  thereby  freed  from  indulging 
in  false  hopes,  but  are  forced  to  the  conviction 
that  "  nurture  "  is  more  important  than  ever  ? 
Although  what  is  "  acquired "  may  not  be  in- 
herited, what  is  not  inherited  may  be  acquired. 
Thus  we  are  led  to  direct  our  energies  even  more 
strenuously  to  the  business  of  reimpressing  desir- 
able modifications,  and  therefore  to  developing 
our  functions  and  environments  in  the  direction 
of  progress. 

It  may  be,  however,  that  our  methods  must 
change  with  the  change  in  our  expectations.  For 
though  we  can,  by  modification,  directly  influence 
the  individual,  and  in  some  measure  even  control 
the  expression  of  his  inheritance,  it  is  not  through 
modifications  that  we  can  hope  directly  to  influence 
posterity.  Man  is  a  slowly  reproducing,  slowly 
varying  organism.  What  is  above  all  precious  is 
the  conservation  of  good  stock.  No  number  of 
veneering  modifications — superficial  screens  of  or- 
ganic defects — can  atone  for  allowing  a  deteriora- 
tion of  the  germinal  inheritance  to  diffuse  itself 
or  to  accumulate.  For  progress  which  is  really 
organic — for  progress,  that  is,  in  our  natural 
inheritance — we  must  wait,  or  rather  work, 
patiently. 

Even  when  it  is  impossible  to  do  much,  there  is 
practical  importance  in  accuracy — which  is  greatly 
needed  in  connection  with  human  heredity.  How 
slow  of  dying  is,  for  instance,  the  fallacy  that  ancient 
and  powerful  families  are  necessarily  degenerate. 


FACTS    OF   INHERITANCE  175 

In  spite  of  what  Galton  and  other  careful  workers 
have  said,  it  is  persistently  asserted  that  noble 
and  illustrious  families  usually  end  in  sterility — 
a  mistake  largely  due  to  ignoring  the  female  lines 
of  descent. 

INHERITANCE  OF  MORAL  CHARACTER. — In  the 
development  of  "  character  "  much  depends  upon 
early  nurture,  education,  and  surrounding  in- 
fluences generally,  but  how  the  individual  reacts  to 
these  must  largely  depend  on  his  inheritance. 
Truly  the  individual  himself  makes  his  own 
character,  but  what  does  that  mean  but  the 
habitual  adjustment  of  an  hereditarily  determined 
constitution  to  surrounding  influence  ?  Nurture 
supplies  the  stimulus  for  the  expression  of  the 
moral  inheritance,  and  how  far  the  inheritance 
can  express  itself  depends  on  the  nurture-stimuli 
available  just  as  surely  as  the  result  of  nurture  is 
conditioned  by  the  hereditarily  determined  nature 
on  which  it  operates.  It  may  be  urged  that 
character,  being  a  product  of  habitual  modes  of 
feeling,  thinking,  and  acting,  cannot  be  spoken  of 
as  inherited,  but  bodily  character  is  similarly  a 
product  dependent  upon  vital  experience.  Some 
children  are  "  born  good  "  or  "  born  bad,"  just 
as  some  children  are  born  strong  and  others  weak, 
some  energetic  and  others  "  tired  "  or  "  old." 

It  is  entirely  useless  to  boggle  over  the  difficulty 
that  we  are  unable  to  conceive  how  dispositions  for 
good  or  ill  lie  implicit  within  the  protoplasmic  unit 
in  which  the  individual  life  begins.  The  fact  is 
undoubted  that  the  initiatives  of  moral  character 
are  in  some  degree  transmissible,  though,  from  the 
nature  of  the  case,  the  influences  of  education, 
example,  environment,  and  the  like,  are  here  more 


176       DARWINISM   AND   HUMAN   LIFE 

potent  than  in  regard  to  structural  features.  We 
cannot  make  a  silk  purse  out  of  a  sow's  ear,  though 
the  plasticity  of  character  under  nurture  is  a  fact 
which  gives  us  all  hope.  Explain  it  we  cannot, 
but  the  transmission  of  the  raw  material  of 
character  is  a  fact,  and  we  must  still  say,  with  Sir 
Thomas  Browne  :  "  Bless  not  thyself  that  thou 
wert  born  in  Athens ;  but,  among  thy  multiplied 
acknowledgments,  lift  up  one  hand  to  heaven 
that  thou  wert  born  of  honest  parents,  that 
modesty,  humility,  and  veracity  lay  in  the  same 
egg,  and  came  into  the  world  with  thee." 

THREE  GENERAL  CONCLUSIONS. — (1)  The  study 
of  inheritance  is  apt  to  leave  a  fatalistic  impression 
in  the  mind,  and  to  some  extent  this  is  justified. 
We  cannot  get  away  from  our  inheritance.  As 
the  poet  Heine  said,  half  laughingly  half  bitterly : 
"  A  man  should  be  very  careful  in  the  selection  of 
his  parents."  On  the  other  hand,  looking  forward, 
we  may  change  the  word  "  parent  "  into  "  partner/' 
recognising  that  a  good  inheritance  is  the  most 
precious  of  all  possessions,  and  that  it  should  be 
guarded  from  mixture  with  bad  stock. 

(2)  But,  again,  the  conclusion  is  strongly  borne 
in  on  us  that  a  good  nurture  is  the  necessary  comple- 
ment of  a  good  nature  and  the  individual  corrective 
of  a  poor  nature. 

(3)  If  there  is  little  or  no  scientific  warrant  for 
our  being  other  than  extremely  sceptical  at  present 
as  to  the  inheritance  of  acquired  characters — or 
better,    the    transmission    of    modifications — this 
scepticism  lends  greater  importance  than  ever,  on 
the  one  hand,  to  a  good  "  nature,"  to  secure  which 
is  the  business  of  careful  mating  ;  and,  on  the  other 
hand,  to  a  good  "  nurture,"  to  secure  which  for  our 


FACTS   OF   INHERITANCE  177 

children  is  one  of  the  most  obvious  and  binding 
duties  :  the  hopefulness  of  the  task  resting  especi- 
ally upon  the  fact  that,  unlike  the  beasts  that 
perish,  man  has  a  lasting  external  heritage  of 
ideas  and  ideals,  embodied  in  prose  and  verse,  in 
statue  and  painting,  in  cathedral  and  university, 
in  tradition  and  convention,  and  above  all  in 
society  itself. 


12 


CHAPTER  VI 
SELECTION:    ORGANIC  AND  SOCIAL 


179 


CHAPTEE  VI 

SELECTION  :     ORGANIC  AND   SOCIAL 

Influence  of  Malthas — Darwin's  Position — The  Theory  stated — The 
Theory  of  Natural  Selection  to  be  tested  as  an  Interpretative 
Formula — Illustrations  of  Natural  Selection — Objections  and 
Criticisms  —  Adaptations — Changes  since  Darwin's  Day — 
Evidences  of  Natural  Selection — Lessening  the  Burden  of  the 
Theory — Sexual  Selection — Isolation — Gradual  Diminution  of 
Natural  Selection  in  Mankind — Contrast  between  the  Human 
Race  and  the  Animal  World — Some  Natural  Selection 
remains — The  Dilemma  of  Civilisation — The  extreme  laissez- 
faire  Position — Social  Surgery — How  far  is  Social  Selection 
compensating  for  Diminished  Natural  Selection  ? — Reversed 
Selection  in  Human  Society — Summary  of  the  Argument — 
Constructive  Suggestions — Selection  of  Eutopias — Selection  of 
Healthful  Occupations — Eugenic  Selection. 

DARWIN  is  often  called  the  Newton  of  biology, 
though  some  say  he  was  rather  its  Copernicus. 
In  any  case,  he  discerned  in  nature  the  working  of 
a  great  process,  which  has  helped  us  to  understand 
how  things  have  come  to  be  as  they  are.  Among 
his  services  there  is  none  greater  than  this,  that  he 
discovered  the  efficacy  of  Natural  Selection,  which 
means  Nature's  sifting.  The  raw  materials  are 
inborn  variations ;  the  internal  condition  is  the 
heritability  of  the  favourable  variations;  the 
external  condition  is  the  struggle  for  existence  ; 
the  process  of  sifting  is  discriminate  elimination ; 
the  result  is  the  survival  of  the  fittest  to  the  given 
conditions. 
INFLUENCE  OF  MALTHUS. — Adumbrations  of  the 

181 


182       DARWINISM   AND   HUMAN   LIFE 

general  idea  of  selection  are  to  be  found  in  various 
pre-Darwinian  documents,1  but  it  was  to  Malthus 
only  that  Darwin,  who  was  very  generous  in  dealing 
with  anticipations,  owned  any  debt.  He  speaks 
of  this  in  a  well-known  passage  in  his  "  Autobio- 
graphy " :  "  In  October,  1838,  fifteen  months  after 
I  had  begun  my  systematic  inquiry,  I  happened 
to  read  for  amusement  '  Malthus  on  Population/ 
and,  being  well  prepared  to  appreciate  the  struggle 
for  existence  which  everywhere  goes  on  from 
long-continued  observations  of  the  habits  of  animals 
and  plants,  it  at  once  struck  me  that,  under  these 
circumstances,  favourable  variations  would  tend 
to  be  preserved  and  unfavourable  ones  to  be 
destroyed.  The  result  of  this  would  be  the  forma- 
tion of  new  species.  Here,  then,  I  had  at  last  got  a 
theory  by  which  to  work." 

Twenty  years  after — Darwin  having  'published  no 
theory  meanwhile — history  repeated  itself.  Alfred 
Russel  Wallace  was  collecting  insects  at  Ternate 
and  suffering  badly  from  fever.  As  he  was  resting 
one  day  between  fits,  he  happened  to  recall  Malthus' 
"  Principles  of  Population  "  which  he  had  read 
about  twelve  years  before — the  first  book  that  he 
had  come  across  approaching  philosophical  biology. 
He  thought  of  what  Malthus  had  said  regarding 
the  way  disease,  famine,  and  war  keep  down  the 
population  of  savage  races  to  a  much  lower  average 
than  that  of  civilised  peoples ;  he  thought  of  the 
similar  elimination  that  goes  on  in  the  animal 
world,  and  it  occurred  to  him  to  ask  the  question, 
"  Why  do  some  die  and  some  live  ?  "  "  And  the 
answer  was,  clearly,  that  on  the  whole  the  best 
fitted  live.  From  the  effects  of  disease  the  most 

»  E.g.  by  Charles  Wells,  Patrick  Matthew,  James  Cowles  Prichard. 


SELECTION:    ORGANIC   AND   SOCIAL   183 

healthy  escaped ;  from  enemies,  the  strongest, 
the  swiftest,  or  the  most  cunning ;  from  famine, 
the  best  hunters  or  those  with  the  best  digestion  ; 
and  so  on.  Then  it  suddenly  flashed  upon  me 
that  this  self-acting  process  would  necessarily 
improve  the  race,  because  in  every  generation  the 
inferior  would  inevitably  be  killed  off  and  the 
superior — that  is,  the  fittest — would  survive.  Then 
at  once  I  seemed  to  see  the  whole  effect  of  this.  . .  ." 
His  words  in  the  1858  paper  were  :  "  If  any  species 
should  produce  a  variety  having  slightly  increased 
powers  of  preserving  existence,  that  variety  must 
inevitably  in  time  acquire  a  superiority  in  numbers." 
Thus,  for  the  second  time,  from  the  domain  of 
human  society  the  idea  of  natural  selection  was 
suggested. 

Perhaps  the  suggestion  was  made  a  third  time, 
for  it  is  an  interesting  fact  that  in  1852 — six  years 
before  the  theory  of  natural  selection  was  launched 
by  Darwin  and  Wallace,  when  Herbert  Spencer 
wrote  his  famous  evolutionist  article  on  "  The 
Development  Hypothesis,"  he  published  another 
important  essay  entitled,  "  A  Theory  of  Popula- 
tion," toward  the  close  of  which  he  came  within  an 
ace  of  recognising  that  the  struggle  for  existence 
was  a  factor  in  organic  evolution.  Spencer  was 
not  guilty  of  reading  much,  but  it  would  be  striking 
if  he  too  had  been  stimulated  by  Malthus.  In  any 
case  we  have  the  fact  that,  at  a  time  when  pressure 
of  population  was  practically  interesting  men's 
minds,  Darwin,  Wallace,  and  Spencer  were  in- 
dependently led  towards  a  theory  of  organic 
evolution.  There  could  be  no  better  illustration 
of  the  Comtian  thesis  that  science  is  a  social 
phenomenon.  Prof.  Patrick  Geddes  suggests  that 


184       DARWINISM   AND    HUMAN    LIFE 

the  severity  of  industrial  competition,  which  had 
increased  bitterly  between  Malthus's  time  and 
Darwin's,  was  at  least  subconsciously  in  the  mind 
of  both  Darwin  and  Wallace,  and  gave  spring  to 
the  theory  which  they  projected  upon  nature.1 

DARWIN'S  POSITION. — Let  us  try  to  understand 
Darwin's  problem.  His  studies  as  a  naturalist 
had  made  him  acquainted  with  a  large  number  of 
animals  and  plants,  and  two  facts  had  especially 
impressed  him:  first,  that  the  various  kinds  are 
suited  to  the  niches  which  they  fill — suited  often 
as  hand  to  glove ;  and  second,  that  in  many  cases 
the  various  kinds  are  closely  linked  together  by 
resemblances  which  evidently  mean  blood-relation- 
ship. What  Darwin  wished  to  get  at  was  a  theory 
of  the  origin  of  one  species  from  another,  and  a 
theory  of  the  origin  of  the  adaptations  with  which 
the  world  of  life  is  full.  He  found  the  answer  to 
both  his  questions  in  discovering  a  process  actually 
at  work — Nature's  sifting  of  the  changes  that  crop 
up.  He  defined  it  as  "  the  preservation,  during 
the  battle  for  life,  of  varieties  which  possess  any 
advantage  in  structure,  constitution,  or  instinct." 

1  Following  Bacon,  we  may  draw  a  useful  distinction  between 
a  scientific  theory  in  the  stage  of  suggestion — an  anticipation  of 
nature,  and  a  scientific  theory  in  the  stage  of  verification — an  inter- 
pretation of  nature.  In  the  stage  of  suggestion  the  theory  of 
natural  selection  was  in  greater  part  sociomorphic ;  but  it  passed, 
by  Darwin's  careful  workmanship,  into  the  stage  of  verification, 
and  it  should  be  remembered  that  the  validity  of  a  scientific  theory 
is  not  affected  by  what  suggested  it.  A  theory  is  to  be  estimated 
by  its  power  of  formulating  a  definite  order  of  facts. 

At  the  same  time  those  who  insist  on  using  the  formula  of  natural 
selection  in  the  interpretation  of  human  affairs,  and  who  call  it 
a  biological  formula,  must  remember  the  history — that  it  was  from 
the  human  domain  that  the  suggestion  of  the  theory  came.  Per- 
haps there  is  some  supplementary  suggestion  from  human  s  ociety, 
equally  valuable,  which  no  Darwin  has  yet  arisen  to  appreciate. 


SELECTION:    ORGANIC   AND   SOCIAL   185 

His  general  line  of  thought  was  something  like 
this.  The  gardener  and  the  breeder  watch  for 
changes  or  variations  ;  they  select  for  propagation 
those  variants  that  please  them,  keeping  all  others 
away  ;  gradually  they  establish  new  varieties  that 
breed  true.  So  it  is  in  nature,  Darwin  said,  where 
variations  are  continually  cropping  up.  But  what 
takes  the  place  of  the  breeder  ?  Nature's  sifting 
in  the  struggle  for  existence.  Man  has  done  much 
in  a  short  time;  what  may  Nature  not  have 
done  in  a  long  time  ?  As  has  often  been  pointed 
out,  there  are  some  differences  in  detail  between 
artificial  and  natural  selection,  but  the  essential 
features  are  the  same. 

"  The  theory  of  natural  selection,"  Mr.  Wallace 
writes,1  "  commonly  called  Darwinism,  is  one  of 
the  most  simple  and  easy  of  comprehension  in  the 
whole  range  of  science ;  yet,  after  fifty  years  of 
continuous  exposition  and  study,  there  is  perhaps 
none  that  is  so  widely  and  persistently  misunder- 
stood." Let  us  therefore  linger  over  it. 

When  one  visits  that  scientific  Aladdin's  cave 
called  the  British  Museum  (Natural  History),  one 
is  impressed,  on  entering,  by  the  statue  of  Darwin, 
and  from  it  the  eye  falls  to  a  tree  full  of  pigeons 
with  the  wild  rock-dove  (Columba  livia)  as  a  centre, 
and  on  the  branches  round  about  Pouters  and 
Carriers,  Tumblers  and  Trumpeters,  Jacobins  and 
Fantails,  and  other  breeds.  That  case  of  pigeons 
is  a  Darwinian  diagram,  for  Darwin  chose  these 
birds  for  special  study — and  they  led  him  to  a 
goal  as  famous  as  Ararat.  There  are  over  two 
hundred  very  well-marked  breeds  of  domestic 
pigeons,  and  there  are  at  least  ten  that  would  be 

1  Fortnightly  Beview  (March  1909),  p.  411. 


186       DARWINISM   AND   HUMAN   LIFE 

ranked  as  distinct  genera  if  they  occurred  wild. 
Yet  there  is  strong  evidence  that  all  are  scions 
of  the  blue  rock-pigeon  (Columba  lima).  Darwin 
pointed  out  that  the  social,  non-arboreal  habits, 
the  mode  of  cooing,  and  other  characters  of 
domestic  pigeons,  point  to  Columba  lima ;  that 
this  bird  has  a  wide  range  of  distribution;  that 
it  is  very  variable  in  plumage,  easily  tamed,  and 
actually  domesticated ;  that  all  races  of  domestic 
pigeons  are  fertile  when  crossed,  and  their  off- 
spring are  usually  fertile — two  facts  which  point 
to  one  origin  for  all ;  that  all  domestic  pigeons 
tend  to  revert  to  the  blue  rock-pigeon;  and 
so  on. 

In  the  same  way,  as  is  well  known,  Darwin 
brought  forward  evidence  that  all  the  breeds  of 
poultry — Hamburghs  and  Dorkings,  Bantams  and 
Silk-fowl,  and  all  the  rest  of  them — are  descended 
from  the  jungle- fowl,  Gallus  banJciva,  which  is 
still  found  wild  in  some  parts  of  India  and  the 
Malay  Islands.  There  seems  to  be  evidence  that 
the  jungle-fowl — which  our  gamecock  most  nearly 
resembles — was  domesticated  in  the  East  before 
1400  B.C.,  and  was  introduced  into  Europe  about 
600  B.C.  The  clear  cases  of  pigeon  and  fowl  were 
backed  up  by  more  difficult  cases,  such  as  those 
of  horse  and  dog,  where  it  seems  almost  certain 
that  the  domesticated  breeds  have  arisen  from 
several  distinct  wild  species. 

At  all  events,  Darwin  proved,  up  to  the  hilt,  that 
the  breeder  is  a  transformist.  Circe  changed  men 
into  pigs  ;  the  prehistoric  breeders  made  a  wolfish 
creature  into  a  trustworthy  guardian  of  their 
flocks.  What  is  the  method  ?  The  breeder  can- 
not create ;  he  waits  for  what  turns  up,  and  then  he, 


SELECTION:    ORGANIC   AND   SOCIAL   187 

directs.  He  directs  by  bringing  similars  together 
and  by  eliminating  undesirables  from  the  flock 
or  herd.  So  Nature  directs — but  automatically 
— by  singling  and  sifting  in  the  struggle  for 
existence. 

THE  THEORY  STATED. — (1)  Darwin  started  with 
the  fountain  of  change  within  the  living  creature, 
whence  variations  are  always  welling  forth.  Off- 
spring are  not  quite  like  their  parents,  or  like  one 
another.  It  is  a  fact  that  there  are  individual 
variations,  for  better  and  for  worse,  between  living 
creatures  of  the  same  kind.  In  some  cases  it  is 
definitely  known  that  these  variations  may  be 
transmitted. 

(2)  Life  is  very  prolific,  and  in  every  kind  of 
living  creature — except  man — the  majority  die 
young.  There  is  not  usually  any  increase  in 
numbers  from  generation  to  generation.  There 
is  a  ceaseless  struggle  for  existence — a  phrase  to 
be  taken  in  a  wide  and  metaphorical  sense  as  a 
description  of  what  goes  on  in  nature  because  of 
the  limits  of  space  and  the  self-assertiveness  of  the 
individual,  because  of  the  prolific  multiplication 
of  the  eaters  and  the  insufficiently  rapid  supply  of 
the  eatable,  because  of  the  changeful  and  merciless 
physical  environment,  and  all  the  subtle  interrela- 
tions of  things  in  the  web  of  life,  whose  warp  and 
woof  are  love  and  hunger. 

It  is  very  important  to  realise  the  web  of  life 
in  this  connection,  for,  as  an  acute  critic  points  out, 
it  alone  warrants  us  in  believing  that  "  slight 
differences  may  give  one  creature  an  advantage 
over  its  neighbour  in  a  nicely  balanced  struggle  for 
life.  In  other  words,  it  introduces  the  conception 
of  a  correlation  between  even  minute  variations  and 


188       DARWINISM   AND   HUMAN   LIFE 

the  survival  or  non-survival  of  their  possessors."  l 
As  Darwin  says,  in  a  notable  passage  :  "  Battle 
within  battle  must  be  continually  recurring,  with 
varying  success;  and  yet,  in  the  long  run,  the 
forces  are  so  nicely  balanced  that  the  merest  trifle 
would  give  the  victory  to  one  organic  being  over 
another." 

(3)  The  theory  continues,  that,  if  variations  occur 
in  the  direction  of  increased  fitness,  and  if  the 
variations  are  heritable,  and  if  there  is  discriminate 
elimination  with  reference  to  these  variations, 
then  the  possessors  of  the  fitter  variations  must  be 
favoured  with  longer  life  and  larger  families — with 
survival,  in  short.  And  if  this  is  kept  up  con- 
sistently, then  new  adaptations,  and,  with  the  help 
of  isolation,  new  species,  will  arise.  Those  mem- 
bers of  a  species  that  are  handicapped  will  become 
a  minority  and  eventually  their  type  will  be 
eliminated.  Those  that  have  varied  so  as  to  be  in 
any  appreciable  way  favoured  will  become  the 
majority,  and  eventually  the  type,  of  the  species. 

A  little  reflection  will  show  that  there  are  two 
main  modes  of  natural  selection.  It  may  produce 
its  effects  by  the  discriminate  elimination  of  the 
less  fit,  or  by  the  increased  and  more  effective 
reproductivity  incident  on  the  success  of  the  more 
fit.  These  two  modes  are  sometimes  distinguished 
as  Lethal  and  Reproductive  Selection  respectively. 
In  both  cases  the  fitter  members  of  a  generation 
contribute  more  than  the  less  fit  to  the  next  genera- 
tion. If  we  regard  sexual  selection  as  a  special 
case  of  natural  selection,  which  seems  the  clearest 
view,  we  have  to  include  extreme  cases  like  that 

1  "  Evidence  of  Natural  Selection,"  by  E.  S.  Russell,  in  Rivisla 
di  Scienza  (1908),  vol.  iii. 


SELECTION:    ORGANIC   AND   SOCIAL   189 

of  the  single  drone  that  overtakes  the  queen-bee 
in  her  nuptial  flight — all  the  others  being  left  to 
die  non-reproductive. 

Darwin  summed  up  the  theory  in  a  couple  of 
sentences :  "  As  many  more  individuals  of  each 
species  are  born  than  can  possibly  survive,  and 
as,  consequently,  there  is  frequently  recurring 
struggle  for  existence,  it  follows  that  any  being, 
if  it  vary  however  slightly  in  any  manner  profitable 
to  itself,  under  the  complex  and  sometimes  varying 
conditions  of  life,  will  have  a  better  chance  of 
surviving,  and  thus  be  naturally  selected.  From 
the  strong  principle  of  inheritance  any  selected 
variety  will  tend  to  propagate  its  new  and  modified 
form." 

THE  THEORY  OF  NATUEAL  SELECTION  TO  BE 
TESTED  AS  AN  INTERPRETATIVE  FORMULA. — For 
what  has  occurred  in  the  past  the  theory  of  natural 
selection  can  never  be  proved ;  we  can  only  show 
that  it  offers  a  reasonable  interpretation,  that  it  is 
a  formula  that  fits.  In  the  case  of  many  of  the 
most  remarkable  adaptations,  such  as  those  of 
mimicry  and  protective  resemblance,  it  is  the  only 
interpretation  in  the  field  that  has  any  approach  to 
feasibility. 

In  regard  to  what  is  going  on  at  present,  several 
attempts  have  been  made  (as  we  shall  see  later) 
to  catch  natural  selection  at  work,  to  prove  the 
occurrence  of  discriminate  elimination  with  refer- 
ence to  a  particular  character,  to  show  that  what 
determines  that  one  organism  should  be  taken 
and  another  left  is  that  the  first  lacked  something 
which  the  survivor  has.  This  is  extremely  im- 
portant, for  it  is  "  as  easy  as  winking  "  to  imagine 
possible  utilities  for  a  particular  character,  whereas 


190       DARWINISM   AND   HUMAN    LIFE 

it  is  our  business  to  prove  that  the  survivors  survive 
because  they  have  the  character  in  question. 

ILLUSTRATIONS  OP  NATURAL  SELECTION. — In  the 
1858  essay  Darwin  gave  the  following  imaginary 
illustration.  Some  dog-like  animal  lives  on  rabbits, 
and  on  hares,  when  it  can  get  them ;  the  rabbits 
become  scarcer,  and  the  hares  more  plentiful,  so 
the  carnivore  turns  its  attention  to  hares ;  those 
carnivores  that  varied  in  the  direction  of  swiftness 
and  sharp-sightedness  would  get  on  best,  would  be 
more  successful  as  regards  numbers  and  vigour  of 
offspring ;  in  a  thousand  generations  there  would 
be  a  marked  effect — as  surely,  he  said,  as  grey- 
hounds can  be  improved  by  selection  and  careful 
breeding. 

Many  insects  in  Madeira  have  reduced  and 
useless  wings,  or  none,  while  their  allies  in  Europe 
have  them  well  developed.  The  Darwinian  inter- 
pretation is,  that  as  Madeira,  like  similar  islands, 
is  exposed  to  sudden  gales,  the  flying  insects  have 
been  blown  out  to  sea,  while  those  that  varied  in 
the  direction  of  Sightlessness  have  survived.  It 
is  easy  to  make  fun  of  this,  as  Samuel  Butler  did 
when  he  said  it  was  like  explaining  our  own 
presence  by  the  fact  that  our  cousins,  uncles,  and 
aunts  had  gone  away.  A  little  reflection,  however, 
will  show  that  the  theory  fits  the  facts,  and  our 
confidence  in  the  interpretation  grows  when  we 
find  that  other  exposed  and  wind-swept  islands 
agree  with  Madeira  in  having  flightless  insects. 
Thus,  in  the  stormy  and  shelterless  Kerguelen  all 
the  insects  (including  a  moth,  several  flies,  and 
many  beetles)  are  flightless  and  most  are  wingless. 

Many  Arctic  mammals  and  birds — such  as  fox 
and  falcon — have  a  beautiful  white  colour ;  what 


SELECTION:    ORGANIC   AND   SOCIAL   191 

is  the  selectionist  interpretation  of  this  charac- 
teristic ?  The  first  step  is  to  recognise  that  animals 
are  very  variable  as  regards  colouring,  and  thus 
there  is  raw  material  to  work  on.  Furthermore,  a 
variation  in  the  direction  of  whiteness  is  common — 
white  blackbirds  and  swallows,  white  rats  and 
moles,  being  well  known.  It  seems  likely  that  a 
ferment  essential  to  the  manufacture  of  the  pig- 
ment drops  out  of  the  inheritance  of  these 
albinos.  The  change  is  of  germinal  origin,  and 
it  is  hereditary.  Now  there  is  a  keen  struggle 
for  existence  in  Arctic  regions,  and  any  character 
that  gives  its  possessor  a  pull  is  likely  to  have 
selective  value.  But  there  are  various  advan- 
tages in  a  white  dress  in  snowy  regions — it  is 
the  least  conspicuous  and  the  most  comfortable. 
Those  who  turn  white  will  get  on  best,  other  things 
being  equal.  Therefore  we  have  white  races  in 
Arctic  regions,  and  we  may  corroborate  the 
argument  by  referring  to  a  simple  experiment. 
Prof.  Davenport  had  300  chickens  in  a  field,  80 
per  cent,  white  or  black  and  conspicuous,  20  per 
cent,  spotted  and  inconspicuous.  In  a  short  time 
twenty-four  were  killed  by  crows,  but  only  one 
of  the  killed  was  spotted. 

In  a  heavy  snowstorm  at  Johannesburg  in 
August  1909,  many  hundreds  of  trees  were  destroyed 
by  the  weight  of  snow  on  the  branches.  It  was 
interesting,  after  the  storm,  to  notice  that  the 
elimination  was  in  a  marked  degree  discriminate. 
The  trees  that  suffered  most  were  the  imported 
Australian  trees,  such  as  Blue  Gums  and  Black 
Wattles,  quickly  growing,  with  soft  wood,  and 
with  abundant  foliage  that  caught  the  snow.  On 
the  other  hand,  the  deodars  from  the  Himalaya 


192       DARWINISM   AND   HUMAN    LIFE 

Mountains,  constitutionally  adapted  to  let  the 
snow  slide  from  their  pendulous  branches  and 
acicular  leaves,  had  hardly  a  twig  broken.  If 
similar  storms  occurred  several  times  a  year,  instead 
of  once  in  twenty  years,  there  would  soon  be  no 
Blue  Gums  or  Wattles. 

OBJECTIONS  AND  CRITICISMS. — Darwin's  sugges- 
tion was  that  new  adaptations,  new  varieties,  new 
species  have  arisen  by  the  elimination  of  the 
relatively  unfit  variants  and  by  the  selection  of 
the  relatively  fit.  In  other  words,  natural  selection 
is  the  main  directive  factor  in  evolution.  That  is 
to  say,  given  variations,  the  secret  of  success  is 
sifting.  Against  this  theory  all  manner  of  objec- 
tions have  been  urged — fair  and  unfair,  competent 
and  incompetent,  wise  and  foolish.  The  army  of 
objections  is  so  huge  that  one  feels  there  must  be 
strong  virtue  in  a  theory  that  is  so  vigorous  after 
fifty  years.  It  should  always  be  remembered 
that  the  best  and  the  severest  critic  of  the  theory 
of  natural  selection  was  Charles  Darwin  himself.1 
We  do  not  propose  to  defend  the  theory  or  to 
slay  the  thrice  slain,  but  the  following  statements 
may  serve  to  remove  some  common  misunder- 
standings. 

(1)  It   must   be   clearly   understood   that   the 
"  fittest "  which  survive  are  not  necessarily  best 
or  highest  on  any  absolute  standard,  but  simply 
fittest  for  the  given  conditions.    The  liver-fluke  is 
"  fit,"  as  well  as  the  sheep. 

(2)  Until  we  know  more  about  the  origin  of 
the  variations  which  form  the  raw  material  of 

1  An  admirable  statement  of  the  objections  to  the  theory  of 
natural  selection,  and  an  answer  to  them,  will  be  found  in  Prof. 
Plate's  "  Handbook  to  Darwinism."  (Leipsig,  1908.) 


SELECTION:    ORGANIC   AND    SOCIAL    193 

progress  we  are  open  to  the  reproach  of  giving 
a  theory  of  the  survival,  but  not  of  the  arrival 
of  the  fittest.  Yet  there  are  often  two  misunder- 
standings in  the  minds  of  those  who  play  with 
this  reproach,  which  Darwin  met  long  ago.  (a)  It 
is,  of  course,  clear  that  natural  selection  is  Siva, 
the  Destroyer,1  and  that  L'Evolution  creatrice  is 
the  secret  of  the  organism.  Natural  selection 
prunes  a  growing  and  changeful  tree.  Natural 
selection  is  a  directive,  not  an  originative,  factor. 
The  problem  of  origins  is  the  problem  of  variation. 
(b)  It  must  also  be  noted  that,  if  the  fittest  have 
arisen  by  very  gradual  steps,  by  the  accumulation 
of  variations  small  in  amount,  then  the  reproach 
of  explaining,  not  the  arrival,  but  only  the  survival, 
loses  much  of  its  force. 

(3)  With  unwearying  reiteration  the  objection 
is  raised  that  the  initial  stages  of  new  adaptations 
will  be  too  minute  to  have  survival  value.  This 
difficulty  has  been  often  dealt  with,  and  it  may 
suffice  here  to  point  out  (a)  that  no  one  can 
decide,  in  an  a  priori  way,  how  small  a  change  may 
be  of  critical  moment ;  (6)  that  in  the  fine  texture 
of  the  web  of  life  a  trivial  difference,  as  Darwin 
said,  may  determine  survival ;  (c)  that  elimination 
may  be  effective  though  it  is  not  accomplished  in 
a  generation ;  and  (d)  that  an  incipient  change 

1  Most  biologists  admit,  what  Darwin  himself  clearly  recognised, 
that  in  strictness  the  real  process  is  natural  elimination.  As  an 
American  biologist  says:  "  The  fit  are  not  selected — it  is  the  unfit 
who  fail  to  survive,  and  the  fit  are  merely  the  survivors.  The 
process  is  negative  throughout.  A  railway  train  selects  its  pas- 
sengers in  the  same  sense — those  who  come  in  time  get  aboard, 
those  who  do  not,  get  left."  At  the  same  time  it  must  be  under- 
stood that,  although  the  process  is  negative,  the  results  are  in  part 
positive. 

13 


194       DARWINISM    AND    HUMAN   LIFE 

may  be  carried  through  its  initial  stages  by  being 
correlated  with  another  more  important  change. 

(4)  The  eliminative  processes  that  most  Dar- 
winians believe  in,  because  they  see  them  going 
on,  may  be  slow  as  well  as  quick,  gentle  as  well 
as  severe,  environmental  as  well  as  competitive. 
The  selected  are  not  necessarily  those  saved  from 
the  jaws  of  violent  death;  they  may  be  simply 
those  who,  in  virtue  of  a  heritable  peculiarity,  have 
a  rather  longer  and  more  successful  life  and  a 
rather  larger  and  more  successful  family.  The 
only  eliminative  processes  that  can  be  believed 
in  as  counting  for  much  in  evolution  are  those 
which  are  discriminate  and  consistent.  Thinning 
turnips  may  serve  as  our  diagram  of  indiscriminate 
elimination  (only  very  indirectly  does  it  improve 
the  turnip  race)  ;  Luther  Burbank  carefully 
burning  some  of  his  most  interesting  creations 
because  they  are  not  quite  right  for  his  purpose 
may  serve  as  our  diagram  of  discriminate  elimina- 
tion. But  while  the  modes  of  natural  selection 
are  many  and  various,  the  logic  of  the  process 
is  always  the  same — when  a  heritable  peculiarity 
is  of  critical  moment  in  favouring  survival  it  will 
tend  to  persist,  provided  (a)  that  its  occurrence 
is  sufficiently  frequent,  and  (b)  that  the  dis- 
criminate selection  fostering  it  is  kept  up  con- 
sistently for  a  long  enough  period. 

ADAPTATIONS. — No  one  can  rightly  appreciate 
the  theory  of  natural  selection  who  does  not 
realise  in  some  measure  the  universal  occurrence 
of  those  detailed  fitnesses  of  structure  and  function 
which  are  called  adaptations.1  The  general  idea 

1  We  use  the  word  adaptation  to  express  a  result  achieved  ;  it  is 
sometimes  used  to  express  the  process  of  reaching  that  result. 


SELECTION:     ORGANIC   AND    SOCIAL    195 

of  fitness  is  familiar ;  we  are  irresistibly  pleased 
in  our  own  affairs  with  arrangements  like  safety- 
valves  and  regulators  which  bring  about  important 
results  in  an  effective  way ;  we  pour  contempt  on 
tools  that  will  not  work,  on  machines  that  will  not 
go.  But  we  have  not  to  travel  beyond  our  own 
bodies  to  find  illustrations  of  safety-valves  and 
regulators  that  put  to  scorn  all  machinery,  and 
one  of  the  perennial  delights  of  natural  history, 
in  the  wide  sense,  is  its  continual  discovery  of 
fresh  instances  of  hand-and-glove  adaptations. 

There  is  wonderful  fitness  even  in  one  of  the 
lowest  forms  of  life — it  is  always  changing  and  yet 
it  remains  the  same,  it  answers  back  effectively 
to  external  stimuli,  it  grows  and  passes  from  one 
phase  to  another,  it  reproduces  itself,  arid  it  is 
said  that  some  of  the  simplest  never  die.  We 
cannot,  at  present,  get  behind  this  primary 
adaptiveness  of  living  creatures — it  is  implied  in 
what  we  mean  by  living.  It  is  convenient,  however, 
to  keep  the  word  "  adaptation  "  for  something 
super-added  to  what  we  must  take  for  granted, 
and  yet  it  is  difficult  to  draw  the  line.  The  power 
of  growth  is  a  primary  attribute ;  the  capacity  of 
regrowing  a  readily  broken  limb  depends  on 
this ;  and  yet  it  is  difficult  to  understand  why, 
for  instance,  a  chameleon  should  not  be  able  to 
regrow  its  tail,  as  almost  all  other  lizards  can  do, 
unless  we  regard  the  distribution  of  the  regenerative 
capacity  as  adaptive,  adjusted  in  the  course  of 
ages  to  frequently  recurrent  needs.  We  say  that 
the  immunity  which  certain  organisms  have  to 
certain  poisons  is  an  adaptation,  it  has  been 
wrought  out  and  added  on ;  but  is  it  not,  perhaps, 
a  special  case  of  the  immunity  which  even  simple 


196       DARWINISM   AND   HUMAN   LIFE 

organisms  have  to  considerable  accumulations  of 
their  own  self-made  poisons  or  waste-products  ? 

To  illustrate  adaptations  Weismann  takes,  for 
instance,  the  whale-type  among  mammals,  and 
refers  to  "  the  fish-like  form  of  the  body,  the 
hairlessness  of  the  skin,  the  transformation  of 
the  fore-limbs  to  flippers,  the  disappearance  of 
the  hind-limbs  and  the  development  of  tail-flukes, 
the  layer  of  blubber  under  the  skin,  which  affords 
the  protection  from  cold  necessary  to  a  warm- 
blooded animal/'  and  so  on  through  a  long  list. 
The  whale  is  a  great  bundle  of  adaptations  to 
a  mode  of  life  which  is  peculiar  for  a  mammal. 

Whether  we  take  actively  functional  parts, 
such  as  our  own  hand,  or  passively  functional 
structures,  such  as  a  feather ;  whether  we  take 
obvious  features,  such  as  the  typical  spindle-like 
shape  of  fishes,  or  more  recondite  features,  such  as 
the  structure  of  a  bone  ;  whether  we  take  mimicry 
or  migration,  "  wherever  we  tap  organic  nature/' 
as  Romanes  said,  "  it  seems  to  flow  with  purpose." 

Natural  selection  is  the  theory  of  the  indirect 
coming  about  of  this  wide-spread  purposefulness— 
the  possibility  of  variations  in  the  direction  of 
fitness  being  granted.  Lamarckism,  which  assumes 
the  hereditary  accumulation  of  functional  and 
environmental  modifications,  is  a  theory  of  direct 
adaptation — on  the  whole  simpler  than  the  selection 
theory,  but  suffering  from  the  serious  disadvantage 
that  its  fundamental  assumption  is  still  without 
cogent  evidence  in  its  favour. 

Birds'  eggs  are  of  diverse  shapes,  and  we  know 
in  some  detail  the  actual  factors  which  determine 
these.  We  also  know  that  individual  variations 
in  the  shape  are  not  uncommon.  We  can  under- 


SELECTION:     ORGANIC   AND   SOCIAL    197 

stand,  then,  that  if  a  certain  shape  were  particularly 
well  suited  for  special  conditions,  that  shape  would 
be  selected,  i.e.  the  birds  that  were  constitutionally 
unable  to  lay  eggs  of  the  fit  shape  would  be 
eliminated.  Now  Darwin  points  out  that,  in 
sea-birds  like  guillemots  and  razor-bills,  which 
lay  their  eggs  on  the  narrow  ledges  of  precipitous 
cliffs,  the  shape  of  egg  is  very  markedly  top-like. 
The  adaptiveness  of  the  shape  is  that,  if  the  egg 
be  jostled  by  the  parent  or  some  other  bird,  or 
be  caught  in  a  swirl  of  wind,  it  rotates  on  its 
short  axis  without  rolling  from  its  original  position. 

Let  us  take  another  instance.  The  ^Esop  prawn 
(Hippolyte  varians)  may  be  red,  yellow,  blue, 
orange,  olive,  violet,  brown,  green,  and  other 
colours.  It  is  born  without  a  bias  and  it  takes 
on  the  colour  of  its  surroundings,  both  when 
young  and  when  adult.  Put  some  in  a  glass 
aquarium,  and  line  the  sides  and  floor  with  paper 
of  almost  any  colour ;  the  prawn  follows,  and 
from  one  colour  it  may  be  changed  to  any  other. 

As  bright  yellow,  blue,  and  violet  are  not 
common  colours  among  the  seaweed,  it  has  been 
argued  that  the  power  of  colour-change  cannot  be 
the  outcome  of  selection.  But  that  is  an  absurd 
conclusion ;  it  is  by  no  means  certain  that  the 
bright  colours  are  absent  among  seaweed,  and, 
besides,  adaptiveness  is  rarely  perfect. 

Many  colour-adaptations  are  very  striking.  Thus 
Prof.  Poulton  has  shown  that  certain  caterpillars 
will,  within  certain  limits,  take  on  the  colour 
of  their  surroundings,  and  Engelmann  has  shown 
that  the  peculiar  algae  known  as  Oscillatoria 
become  green  in  red  light,  red  in  green  light — 
physiologically  the  best  possible  colours. 


198       DARWINISM   AND    HUMAN    LIFE 

We  may  speak  of  an  organism  as  a  bundle  of 
adaptations,  but  we  are  not  justified  in  saying  that 
every  structure  is  an  adaptation.  There  are  some 
structures  whose  use  is  unknown,  and  there  are 
others  which  seem  to  be  of  no  value,  such  as  well- 
concealed  decorativeness.  It  may  be,  however, 
that  some  of  the  details  whose  significance  is 
unknown  are  the  architectural  correlates  of  im- 
portant characters. 

CHANGES  SINCE  DARWIN'S  DAY. — Darwin  did  not 
doubt  the  legitimacy  of  supposing  that  some  of 
the  direct  effects  of  use  and  disuse  and  of  the 
influence  of  surroundings  may  be  transmitted  as 
such  or  in  a  representative  degree.  He  was, 
therefore,  to  a  limited  extent  a  Lamarckian,  and 
there  are  some  competent  authorities  who  occupy 
a  similar  position.  We  are  far  from  dogmatically 
declaring  that  the  Lamarckian  position  is  quite 
untenable,  but  we  have  hinted  at  some  of  the 
difficulties  which  have  led  us  to  abandon  it  until 
further  evidence  is  forthcoming. 

Leaving  this  as  a  drawn  battle,  we  wish  to 
refer  briefly  to  two  marked  changes  since  Darwin's 
day.  In  the  first  place,  there  has  been  a  useful 
attempt  to  give  some  experimental  demonstration 
of  the  working  of  natural  selection.  In  the 
second  place,  there  is  a  growing  feeling  among 
different  bodies  of  workers  that  it  is  not  necessary 
to  burden  the  shoulders  of  the  natural  selection 
theory  so  heavily  as  heretofore. 

EVIDENCES  OF  NATURAL  SELECTION. — One  of 
the  most  interesting — though,  from  the  nature  of 
the  case,  least  impressive — steps  of  progress  since 
Darwin's  day  is  the  attempt  to  secure  definite 
evidence  of  the  operation  of  natural  selection. 


SELECTION:    ORGANIC   AND    SOCIAL    199 

It  must  be  admitted  that  Darwin  left  the  theory 
in  this  form  :  Variations  occur  abundantly  ;  there 
is  a  complex,  subtle  struggle  for  existence ;  there  is 
a  constant  process  of  sifting  and  winnowing ;  if  fit 
variations  occur  among  the  rest,  and  if  there  is 
discriminate  elimination  so  intense  that  survival 
depends  on  the  presence  or  absence  of  the  variation 
in  question,  then  new  adaptations  must  result. 
Those  who  have  something  of  a  naturalist's  ex- 
perience and  have  some  appreciation  of  the  enor- 
mous scale  upon  which  Nature  works — as  to  time, 
as  to  numbers,  as  to  chances — have  usually  been 
content  to  accept  this  theory  of  natural  selection 
as  a  good  working  hypothesis. 

But  what  we  wish  is  actual  proof  of  discriminate 
elimination,  that  survivors  do  survive  in  virtue  of 
particular  qualities.  A  few  illustrations  in  the 
present  may  legitimise  our  belief  that  similar 
processes  occurred  in  the  past.  Let  us  summarise 
the  best  of  these  illustrations. 

With  silk  threads  Cesnola  *  tethered  forty-five 
green  praying  mantises  to  green  herbage,  and  sixty- 
five  of  the  brown  variety  to  withered  plants.  He 
watched  them  for  seventeen  days,  and  all  survived 
unnoticed  by  birds.  But  when  he  put  twenty-five 
green  ones  among  brown  herbage  all  were  killed 
by  birds  in  eleven  days,  while  of  forty-five  brown 
ones  on  green  grass,  only  ten  survived  at  the  end 
of  seventeen  days.  Here  we  have  definite  proof  of 
a  selective  death-rate,  definite  proof  of  the  selective 
value  of  the  protective  coloration. 

Poulton  and  Saunders  2  fastened  600  pupae  of  the 

1  See  "  Biometrika,"  vol.  iii.  p.  58. 

2  "Report  of  the  British  Association,  Bristol  Meeting"  (1899), 
pp.  906-909. 


200       DARWINISM   AND   HUMAN   LIFE 

tortoise-shell  butterfly  (Vanessa  urticce)  to  nettles, 
tree-trunks,  fences,  walls,  and  so  on.  At  Oxford 
there  was  a  mortality  of  93  per  cent.,  pointing  to 
an  extremely  high  elimination-rate,  and  the  only 
pupae  that  survived  were  on  nettles,  where  they 
were  least  conspicuous.  At  St.  Helens,  in  the  Isle 
of  Wight,  the  elimination  was  92  per  cent,  on  fences 
where  the  pupae  were  conspicuous,  as  against 
57  per  cent,  among  nettles  where  they  were  incon- 
spicuous. Here,  again,  there  is  definite  evidence  of 
discriminate  elimination. 

Another  illustration  is  to  be  found  in  the  late 
Prof.  Weldon's  l  well-known  experiments  on  crabs. 
He  placed  248  male  shore-crabs  (Carcinus  mcenas) 
in  a  vessel  of  sea-water  containing  in  suspension 
a  quantity  of  china-clay ;  and  94  survived.  It  was 
found  that  the  mean  of  the  frontal  breadths  of 
the  survivors  was  distinctly  smaller  than  that  of 
the  eliminated.  "  A  difference  in  the  mean  value 
of  a  character  between  survivors  and  eliminated, 
when  both  have  been  exposed  to  identical  environ- 
mental conditions,  is  proof  that  the  character  is 
being  acted  upon  by  natural  selection.  .  .  ."2  That 
is,  by  the  ordinary  "  secular  selection,"  for  there 
is  another  mode — "  periodic  selection,"  in  which 
the  mean  value  of  the  character  is  not  changed, 
but  extreme  deviations  from  the  mean  are  lopped 
off.  "  Periodic  selection  "  can  be  detected  by  the 
decrease  in  the  range  of  variability. 

Measuring  small  specimens  (10-15  mm.)  of 
shore-crab  taken  from  Plymouth  Sound,  in  the 

»  "  Proc.  Royal  Soc."  (1895),  vol.  Ivii.  pp.  360-79.  Also  Nature 
(1898),  vol.  Iviii.  pp.  499-506  and  595-6. 

2  See  "  The  Evidence  of  Natural  Selection,"  by  E.  S.  Russell, 
jn  Eiiista  di  Scienza  (1908),  voL  ijj. 


SELECTION:     ORGANIC   AND    SOCIAL   201 

years  1893,  1895,  and  1898,  Prof.  Weldon  found 
that,  during  the  time  between  the  first  measure- 
ment and  the  last,  the  frontal  breadth  of  the  crabs, 
taken  relatively  to  their  length,  had  distinctly 
decreased.  As  the  amount  of  suspended  clay  and 
sewage  in  Plymouth  Sound  had  increased  during 
the  same  period,  Prof.  Weldon  concluded  that 
those  with  broad  fronts  were  being  persistently 
eliminated.  As  the  experiment  referred  to  above 
shows,  those  with  narrow  fronts  withstand  the 
muddy  water  better.1  The  inference  was  that  the 
elimination  was  definitely  discriminate. 

Prof.  Bumpus  2  relates  an  interesting  observa- 
tion on  the  house-sparrow  in  North  America. 
After  a  storm  136  were  picked  up  and  brought 
into  the  laboratory,  where  72  revived  and  64  suc- 
cumbed. Survivors  and  eliminated  were  measured 
as  to  length,  size  of  wing,  weight,  length  of  head, 
length  of  humerus,  of  femur,  of  tibio-tarsus,  width 
of  head,  and  length  of  sternum.  For  all  but  the 
last  of  these  characters  the  range  of  variation 
was  considerably  greater  in  those  that  succumbed, 
the  extreme  variants  (e.g.  those  with  longest  as  well 
as  shortest  wing-span)  were  eliminated  (periodic 
selection).  Moreover,  the  survivors  were  a  little 
shorter,  lighter,  longer  in  the  leg,  the  humerus,  and 
the  breast-bone.  General  stability  of  structure,  Prof. 
Bumpus  says,  was  the  essential  characteristic  of 
the  survivors. 

A  fine  proof  of  the  efficacy  of  natural  selection 

1  For  criticism  see  J.  T.  Cunningham,  in  Nature  (1898),  vol.  Iviii. 
pp.  593-4. 

2  "  The  Elimination  of  the  Unfit  as  Illustrated  by  the  Introduced 
Sparrow,"  by  Hermon  C.  Bumpus,  Biol.  Lect.  Woods  Holl,  Boston 
(1898),  pp.  209-26. 


202       DARWINISM   AND    HUMAN   LIFE 

is  given  by  Prof.  H.  E.  Crampton l  for  the  Saturnid 
moth,  Philosamia  cynthia.  A  large  number  of  pupae 
were  collected  from  a  small  areaj  and  kept  till  they 
hatched.  But  only  16'6  per  cent,  of  the  total 
number  collected  gave  perfect  moths.  Many  of 
the  pupae  were  dead  within  the  cocoon  ("  pupal 
elimination  "),  129  out  of  310  died  in  the  period 
between  the  formation  of  the  imago  and  its 
emergence  ("  pupal  imaginal  elimination  ").  Mr. 
Crampton  compared  134  male  pupa?  that  survived 
pupation  with  130  that  died  immediately  after 
pupation,  as  regards  length,  width,  and  depth  of 
the  bust  of  each,  and  as  regards  length  and  breadth 
of  antennae.  Those  that  survived  were  longer, 
narrower  in  the  bust,  and  had  longer,  stouter 
antennae.  Similarly,  he  compared  176  surviving 
female  pupae  with  180  that  died,  and  selection  in 
type  was  found  to  be  certain  for  all  dimensions 
and  to  be  in  the  same  direction  as  in  the  male 
pupae.  The  survivors  were  also  less  variable. 
We  need  not  discuss  the  pupal-imaginal  elimina- 
tion, where  the  results  were  somewhat  different. 
It  is  interesting  to  notice,  as  Mr.  Crampton  points 
out,  that  the  selected  characters  are  not  such  as 
seem  to  be  directly  or  indirectly  "  useful "  to 
their  possessors,  yet  they  are  demonstrated  to  have 
the  high  utility  of  determining  survival — which 
is  indeed,  for  the  evolutionist,  the  final  criterion 
of  utility.3 

We  cannot  do  more  than  allude  to  the  careful 
statistical  methods  by  which  Prof.  Karl  Pearson 
and  others  have  proved  that  there  is  selective 

i  "  Biometrika  "  (1904),  vol.  iii.  pp.  113-30. 
»  See  "  The  Evidence  of  Natural  Selection,"  by  E.  S.  Russell, 
in  Riris'adi  Scienza  (1909),  vol.  iii. 


SELECTION:     ORGANIC   AND   SOCIAL   203 

death-rate  in  man.  A  certain  number  of  people 
are  killed  every  year  in  Britain  by  lightning; 
their  death  is  purely  fortuitous.  But  this  cannot 
be  said  of  phthisis,  where  the  elimination  is  in  part 
quite  definitely  discriminate.  Even  from  the  fact 
that  longevity  is  truly  heritable  it  is  evident  that 
there  must  be  a  selective  death-rate  in  mankind. 

LESSENING  THE  BURDEN  OF  THE  THEORY. — 
another  change  which  seems  now  coming  about  as 
the  result  of  discussion  and  investigation  is  ex- 
pressed in  a  growing  tendency  to  lessen  the  burden 
that  has  been  hitherto  laid — faute  de  mieux — on 
the  shoulders  of  Natural  Selection.  We  cannot 
do  more  than  illustrate  how  different  bodies  of 
workers  are  arriving  at  the  same  general  conclusion. 

(a)  If  we  find  increasing  warrant  for  postulating 
the  occurrence  of  mutations  of  considerable  magni- 
tude and  for  believing  that  they  are  not  readily 
lost  when  they  once  emerge,  then  it  is  not  necessary 
to  suppose  that  every  character  has  arisen  by  the 
accumulation  of  minute  steps.  It  goes  without 
saying  that  mutations  must  pass  through  the 
selection  sieve. 

(6)  Whether  we  postulate  mutations  or  fluctua- 
tions, we  cannot  but  sympathise  with  the  heresy 
which  is  often  whispered,  that  it  is  very  difficult 
to  give  a  concrete  selectionist  interpretation  of 
what  may  be  called  the  "  big  lifts  " l  in  evolution. 

1  The  difficulty  in  regard  to  "  big  lifts  "  is  bound  up  with  the 
question  whether  there  are  any  qualitative  steps  in  evolution,  or 
whether  change  apparently  qualitative  may  not  be  due  to  the 
accumulation  of  minute  quantitative  changes.  It  is  said  that 
there  are  no  transitions  between  a  sledge  and  a  wheeled  cart,  and 
that  a  new  unity  cannot  arise  piecemeal.  It  is  difficult,  however, 
to  feel  confidence  in  these  arguments  from  analogy.  Conscience,  or 
the  habit  of  judging  our  actions  by  a  standard,  is  a  very  distinctive 


204       DARWINISM   AND    HUMAN   LIFE 

Given  heritable  fluctuations  and  selection,  we  can 
perhaps  interpret  the  perfecting  of  an  adaptive 
structure,  such  as  an  elephant's  trunk.  Given 
mutations  and  selection  and  isolation,  we  can 
perhaps  interpret  the  origin  of  a  new  species. 
But  when  we  face  the  "  big  lifts  "  the  difficulty  is 
very  great.  Gymnosperms  have  probably  evolved 
from  fern-like  plants.  But  "  the  seed  and  all  that 
goes  with  it  is  a  new  character,  and  how  selection 
could  have  originated  it  is  a  question  at  whose 
answer  even  scientific  imagination  balks.  It  is 
evident  that  the  ovules  of  Gymnosperms  are  related 
by  descent  to  the  sporangia  of  ferns  in  some  way, 
but  so  extensive  a  change  does  not  seem  to  come 
within  the  possibilities  of  natural  selection."  1 

It  may  be  noted  that  some  palaeobotanists, 
notably  Grand'Eury  and  Zeiller,  maintain  that  the 
rock-record  is  distinctly  suggestive  of  the  sudden 
appearance  of  new  forms  differing  by  marked 
characters  from  those  that  gave  them  birth. 

(c)  Another  view  which  finds  adherents  is  that 
many  minor  characters  are  the  physiological  or 
developmental  concomitants  of  major  characters 
which  have  undeniable  selection- value.  They 
follow  in  the  wake  of  the  more  primary  qualities. 
Thorns  used  to  be  interpreted  by  the  eager  Darwin- 
ians as  a  protection  against  grazing  animals,  and 

human  character,  and  yet  it  is  conceivable  that  it  has  evolved  from 
pre-human  habits  by  a  series  of  very  slight  changes,  some  of  the 
links  being  found  in  self-subordinating  behaviour  among  animals, 
in  parental  care,  in  the  law  of  the  pack.  As  Norman  Wilde  puts  it, 
"  Because  darkness  passes  through  twilight  into  day  by  imper- 
ceptible degrees,  we  do  not  deny  the  difference  in  quality  between 
darkness  and  light." 

1  "  The  Theory  of  Natural  Selection  from  the  Standpoint  of 
Botany,"  by  Prof.  John  M.  Coulter,  in  "  Fifty  Years  of  Darwinism  " 
(1909),  p.  60. 


SELECTION:     ORGANIC   AND   SOCIAL   205 

they  seem  sometimes  to  have  this  value.  But 
this  cannot  be  the  whole  truth.  Apart  from  the 
just  objections  that  thorns  are  often  prevalent  in 
countries  where  there  are  few  grazing  animals  and 
that  they  do  not  appear  in  the  early  stages  when 
they  are  most  needed,  experiment  has  shown  that 
many  thorns  arise  in  response  to  poor  nutrition.1 
Thorns  are  the  natural  outcrops  of  a  kind  of  con- 
stitution suited  to  dry  countries. 

This  idea  was  familiar  enough  to  Darwin,  as  we 
see  from  the  emphasis  which  he  laid  on  instances 
of  "  correlated  variability."  In  this  connection, 
Sir  Ray  Lankester  observed,  at  the  Cambridge 
Centenary  Celebrations  :  "In  my  opinion  he  has 
thus  furnished  the  key  to  the  explanation  of  what 
are  called  useless  specific  characters  and  of  in- 
cipient organs.  That  key  consists  in  the  fact  that 
a  general  physiological  property,  or  character  of 
utility,  is  often  selected  and  perpetuated  which 
carries  with  it  distinct,  even  remote,  correlated 
growths  and  peculiarities  obvious  to  our  eyes,  yet 

1  See  Coulter,  op.  cit.  (1909),  and  Geddes,  "Proc.  Brit.  Aasoo." 
(1889.)  Prof.  Coulter  points  to  significant  facts  like  the  following  : 
the  nettle  can  get  on  quite  well  without  its  stinging  hairs ;  many 
seeds,  especially  in  arid  regions,  develop  a  testa  so  hard  that  it  inter- 
feres with  the  breaking  through  of  the  embryo — which  looks  like 
"  over-adaptation  "  ;  further  investigation  has  played  havoc  with 
the  pretty  story  of  the  extra-floral  nectaries  attracting  a  body-guard 
of  harmless  ants.  It  is  probable  that  in  these  and  a  hundred  other 
cases  our  task  is  rather  that  of  discovering  the  physiological  and 
embryological  significance  of  the  structures  in  question,  than  that 
of  searching  diligently  for  a  utilitarian  justification  which  does 
not  exist.  A  familiar  example  may  bs  found  in  our  finger-prints, 
which  illustrate  discontinuity  in  evolution — the  apparently  abrupt 
origin  of  new  patterns ;  but,  as  we  have  no  warrant  for  supposing 
that  natural  selection  operates  in  any  way  in  this  case,  we  must 
suppose  that  these  patterns  are  the  expressions  of  internal  growth- 
conditions. 


206       DARWINISM   AND    HUMAN   LIFE 

having  no  functional  value.  At  a  later  stage  in 
the  history  of  such  a  form  these  correlated  growths 
may  acquire  value  and  become  the  subject  of 
selection." 

(d)  Among  palaeontologists,  too,  there  are  some, 
like  Prof.  H.  F.  Osborn,  who  make  out  a  strong 
case  for  the  origin  of  new  characters  by  definite 
progressive  variation,  and  "  not  by  the  selection 
of  the  fit  from  the  fortuitous."  In  other  words, 
many  palaeontologists  claim  that  indefinite  varia- 
tions off  the  main  line  are  absent,  so  far  as  the 
rock-record  tells. 

"  The  law  of  gradual  appearance  or  origin  of 
many  new  characters  in  definite  or  determinate 
directions  from  the  very  beginning  I  regard  as 
the  grandest  contribution  which  palaeontology  has 
made  to  evolution." 2  We  must  attach  great 
importance  to  this  expression  of  opinion,  for  it  is 
shared  by  many  who,  like  Prof.  Osborn,  have 
given  their  life  to  studying  the  actual  history ;  but 
it  must  be  borne  in  mind  that  highly  specialised 
types,  like  Ammonites  and  mammals,  may  be  like 
well-pruned  trees — they  may  have  been  selected 
through  long  periods  into  lines  of  determinate 
variation.  The  power  of  divergent  idiosyncrasy 
may  have  been  pruned  out  of  them. 

After  referring  to  the  work  of  Waagen  on 
Ammonites  and  his  own  work  on  mammals  (e.g. 
their  teeth),  Prof.  H.  F.  Osborn  says  :  "  The  law 
of  gradual  change  in  certain  determinate,  definite, 
and,  at  least  in  some  cases,  adaptive  directions, 
through  very  long  periods  of  time,  and  the  absence 

1  Nature  (July  1,  1909),  p.  10. 

2  "  Darwin  and  Palaeontology,"   by  H.   F.   Osborn,  in   "  Fifty 
Years  of  Darwinism  "  (1909). 


SELECTION:     ORGANIC   AND    SOCIAL    207 

of  chance  and  non-direction  in  the  origin  of  a  large 
number  of  adaptive  and  other  new  characters,  is 
the  common  working  principle  both  in  Vertebrate 
and  Invertebrate  palaeontology."1 

(e)  Another  change  of  view — rank  heresy  to  those 
of  the  straiter  sect  of  Darwinians — is  seen  in  the 
writings  of  not  a  few  naturalists  who  do  not  feel 
themselves  bound  to  find  a  use  for  everything. 
There  are  many  apparently  trivial  characters  for 
which  careful  investigation  has  discovered  very 
definite  and  unexpected  utility — Weismann  gives, 
as  an  example,  the  beautiful  microscopic  anchors 
and  discs  of  lime  found  in  the  skin  of  the  burrow- 
ing, worm-like  Holothurians  known  as  Synaptids; 
but,  on  the  other  hand,  the  tyranny  of  an  ex- 
treme zoological  utilitarianism  may  become  absurd. 
When  the  wind  blows  the  long,  sharp-pointed  leaf 
of  the  sand-binding  bent-grass  it  often  makes  a 
perfect  circle  on  the  sand,  but  there  is  no  signifi- 
cance in  this.  Nor  is  there  in  the  beautiful  ripple- 
marks  on  the  sand  or  in  the  frost-flowers  in  the 
window.  It  seems  likely  that  there  are  many 
such  things  in  living  creatures — registrations  of 
orderly  rhythms  of  the  body,  but  not  useful.  The 
barring  on  a  feather  may  be  of  life-saving  value, 
it  may  also  mean  nothing  more  than  diurnal 
variations  in  blood-pressure  when  the  feather  was 
a-making. 

SEXUAL  SELECTION. — As  a  corollary  to  his 
theory  of  natural  selection,  Darwin  expounded  a 
theory  of  sexual  selection,  in  which  he  interpreted 
some  of  the  secondary  peculiarities  of  the  sexes 
as  the  outcome  of  selective  processes  involved  in 
the  combats  of  rival  suitors  and  in  the  choice 

1  Op,  cit.  (1909). 


208       DARWINISM   AND    HUMAN    LIFE 

exercised  by  the  coy  females.  All  sorts  of  mascu- 
line weapons,  such  as  antlers ;  all  sort  of  decora- 
tions, such  as  brilliant  plumage ;  all  sorts  of 
excitants,  such  as  love-calls  and  fragrance,  may 
be  interpreted  in  terms  of  the  sexual  selection 
which  seems  to  occur  in  many  cases,  especially 
where  there  are  more  males  than  females,  or  where 
polygamy  occurs.  The  whole  matter  is  difficult, 
perhaps  more  difficult  than  Darwin  thought,  and 
there  is  great  difference  of  opinion  in  regard  to  it. 
Wallace  does  not  see  his  way  to  believing  at  all 
in  the  action  of  female  choice  ;  Weismann  is  whole- 
heartedly with  Darwin.  It  must  suffice  to  state 
a  few  conclusions  based  on  some  of  the  post- 
Darwinian  contributions  to  this  fascinating  subject. 

(a)  The  combats  of  rival  males  are  often  very 
fierce.     The  younger  or  weaker  candidates  may  be 
killed,    or   expelled,    or   left   unmated.    In   such 
cases  there  seems  little  reason  to  doubt  the  dia- 
criminateness  of  the  elimination.     In  some  curious 
cases,  as  in  spiders,  the  tournaments  are  prolonged, 
but  the  combatants  do  not  seem  to  hurt  one 
another ;    and  it  is  possible  that  the  significance 
of  the  jousting  is  to  excite  the  females,  who  some- 
times stand  by,  as  it  were  interested  spectators. 
In    some    other    cases,    e.g.    among    Lamelhcorn 
beetles  and  Bearded  Monkeys,  there  seems  to  be 
more  bluffing  than  fighting,  for  precedence  is  given 
to  the  candidate  of  most  imposing  appearance. 

(b)  In  regard  to  those  masculine  characters  which 
indubitably  attract  the  female  and  probably  serve 
to  excite  her  and  to  overcome  her  coyness,  there 
seems,   as  Wallace   has  consistently  maintained, 
very  little  evidence  that  the  female  chooses  a 
partner  out  of  a  number  of  suitors.    At  the  same 


SELECTION:     ORGANIC   AND    SOCIAL   209 

time,  there  is  evidence,  in  some  cases,  that  certain 
males  are  left  out  in  the  cold  unmated,  and  that 
these  are  inferior  in  attractiveness  or  in  stimulating 
power. 

(c)  While  the  cases  of  preferential  mating  which 
Darwin  relied  on,  for  instance  among  birds  and 
butterflies,  require  further  study  in  the  light  of 
criticism,  there  is  no  doubt  that  in  many  cases  the 
males  exert  themselves  to  display  their  special 
qualities.    Thus   Prof,   and  Mrs.   Peckham  have 
described,  in  spiders  of  the  family  Attidae,  the  extra- 
ordinary dances  of  the  males  before  the  females. 
That  the  female  literally  chooses  the  handsomest 
dancer  remains  unproved,  yet  it  is  well  known 
that  she  often  punishes  a  suitor  who  does  not 
adequately  please  her  by  killing  him  there  and 
then. 

(d)  In   many  cases,    e.g.   the  antlers  of  stags, 
there  is  a  very  intimate  correlation   between  the 
reproductive  organs  and  the  development  of  the 
secondary  sex  characters.     It  seems  that  an  internal 
secretion  from  the  reproductive   organs  is  neces- 
sary to  start  the  development  of  certain  secondary 
sex  characters.     There  is  also  evidence  that  the 
secondary  differences  between  males  and  females 
hang  together  physiologically,  being  manifold  out- 
crops of  the  deep  constitutional  difference  which 
makes  of  one  animal  an  egg-producer  and  of  another 
a  sperm-producer.     But  this  kind  of  inquiry,  still 
very  incipient,  is  at  a  level  deeper  than  that  of 
sexual  selection,  which  does  not  touch  the  question 
of  origins. 

(e)  It  is  now  generally  believed  that  what  the 
female  chooses  is  not  so  much  slight  improvements 
in  chirping    or  song,  slight  excellences  in  colour 

14 


210       DARWINISM   AN[D   HUMAN    LIFE 

or  scent,  but  rather  the  tout-ensemble  of  that  male 
who  most  excites  her  sexual  interest.  As  Weis- 
mann  says :  "  Even  though  we  certainly  cannot 
assume  that  the  females  exercise  a  conscious  choice 
of  the  '  handsomest '  male,  and  deliberate,  like 
judges  in  a  court  of  justice,  over  the  perfections 
of  their  wooers,  we  have  no  reason  to  doubt  that 
distinctive  forms  (decorative  feathers  and  colours) 
have  a  particularly  exciting  effect  upon  the  female, 
just  as  certain  odours  have  among  animals  of  so 
many  different  groups,  including  the  butterflies." 1 

Though  Darwin  sometimes  seems  to  credit  the 
female  with  no  small  degree  of  aesthetic  fastidious- 
ness, he  also  states  that  "it  is  not  probable  that 
she  consciously  deliberates ;  but  she  is  most 
excited  or  attracted  by  the  most  beautiful,  or 
melodious,  or  gallant  males."  As  Lloyd  Morgan 
says  :  "  The  most  vigorous,  defiant,  and  mettle- 
some male  is  preferred,  just  because  he  alone  affords 
a  contributory  stimulation  adequate  to  evoke  the 
pairing  impulse,  with  its  attendant  emotional 
tone."  From  the  human  point  of  view,  perhaps 
the  most  important  point  is  that,  in  the  course 
of  evolution,  sexual  behaviour  has  come  to  be 
associated  with  psychological  values  which  hitch 
it  to  the  skies. 

ISOLATION. — Besides  selection  in  its  varied  forms 
there  is  another  directive  factor  in  evolution — 
which  Darwin  to  some  extent  recognised — and 
that  is  Isolation.  This  term  is  used  to  include 
all  the  means  which  restrict  the  range  of  inter- 
crossing within  a  species :  geographical  barriers, 
such  as  arise  when  a  peninsula  becomes  an  island ; 
temporal  barriers,  such  as  arise  when  the  members 

1  "  Darwin  and  Modern  Science  "  (1909),  p.  47. 


SELECTION:     ORGANIC   AND    SOCIAL   211 

of  a  species  reach  sexual  maturity  at  different 
times  of  year ;  habitudinal  barriers,  when  a  species 
splits  into  two  or  more  castes  with  different  habits 
of  life ;  physiological  barriers,  such  as  arise  by  some 
variation  in  the  reproductive  organs  ;  and  psycho- 
logical barriers,  which  rest  on  profound  antipathies. 
The  subject  has  been  worked  at  a  good  deal  since 
Darwin's  day,  by  Wagner,  Gulick,  Romanes, 
Jordan,  and  others — and  Romanes  went  the  length 
of  saying  that  Isolation  was  a  sine  qua  non  in  the 
origin  of  new  species.  The  great  difficulty  is  to 
get  a  sufficient  body  of  reliable  facts. 

From  many  passages  in  Darwin's  works  it  is 
evident  that  he  recognised  that  isolation,  or  segrega- 
tion, is  important  in  natural  selection,  just  as  it  is 
in  artificial  selection.  "  I  do  not  doubt,"  he  says, 
"  that  isolation  is  of  considerable  importance  in 
the  formation  of  new  species/'  But  he  did  not 
analyse  the  idea  as  some  post-Darwinian  workers 
have  done. 

When  a  species  spreads,  several  contingents  may 
become  isolated  from  one  another,  and,  if  different 
variations  spring  up  in  the  several  contingents, 
then  the  isolation  will  favour  the  origin  of  distinct 
species.  It  works  in  two  ways  :  (1)  by  preventing 
intercrossing  and  its  possibly  levelling  effects,  and 
(2)  by  involving  close  inbreeding,  which  develops 
prepotency  or  stability  of  type.  There  is  one 
bird  peculiar  to  Britain,  namely,  the  red  grouse, 
but  it  is  closely  allied  to  the  Scandinavian  willow 
grouse,  and  it  seems  impossible  to  doubt  that 
the  literal  isolation  of  Britain  has  allowed  the 
red  grouse  to  diverge  as  a  new  species  from  the 
willow  grouse  stock. 

There  are  said  to  be  eighty  species  of  the  land- 


212       DARWINISM   AND    HUMAN    LIFE 

snail  Cerion  on  the  Bahama  Islands,  and  Gulick 
reports  200-300  species  of  the  land-snail  Acliati- 
nella  in  the  various  valleys  of  the  Sandwich  Island 
Oahu. 

President  Jordan  has  devoted  some  attention 
to  the  occurrence  of  cognate  or  "  geminate " 
species  on  opposite  sides  of  some  barrier.  "  In 
a  general  way,  such  species  agree  with  each  other 
in  all  the  respects  which  usually  distinguish  species 
within  the  genus.  Their  differences  appear  in  minor 
regards,  characters  of  degree,  or  proportion — 
traits  which  we  may  safely  suppose  to  be  of  more 
recent  origin  than  the  ordinary  characters  marking 
off  species  within  the  group."  As  examples  of 
what  are  probably  in  some  measure  the  results 
of  isolation,  he  takes  the  following :  "  Each 
well-separated  island  in  the  West  Indies  has  its 
own  form  of  golden  warbler.  Each  island  in  the 
East  Indies  has  its  own  forms  of  reptiles,  monkeys, 
snails,  and  fresh-water  fishes.  Each  island  in 
Hawaii  has  its  own  species  of  each  genus  of 
Drepanine  birds ;  each  forest  its  own  type  of 
land-snails.  Each  of  the  three  groups  of  rookeries 
in  Bering  Sea  has  its  own  species  of  fur-seal. 
Each  section  of  the  Isthmus  of  Panama  has  its 
geminate  species  of  fishes,  representing  nearly 
every  genus  or  sub-genus  of  the  shore-water  off 
Mexico."  3 

There  is  considerable  evidence  to  show  that 
isolation,  with  its  attendant  inbreeding,  has  played 
an  important  role  in  human  evolution,  fixing  and 
intensifying  and  giving  hereditary  grip  to  types 
which  began  their  career  in  small  communities. 

1  "Isolation  as  a  Factor  in  Organic  Evolution,"  in  "Fifty 
Years  of  Darwinism"  (1909),  p.  81. 


SELECTION:     ORGANIC   AND    SOCIAL   213 

SELECTION   IN   HUMAN   SOCIETY 

GRADUAL  DIMINUTION  OF  NATURAL  SELECTION 
IN  MANKIND. — In  early  days  man  had  probably 
a  precarious  foothold  on  the  earth,  contending 
with  wild  beasts  and  with  physical  conditions  of 
which  he  had  little  mastery.  The  serpent  bit 
his  heel,  the  thorns  cut  his  naked  skin,  the  floods 
rose  and  drowned  him  in  his  cave.  There  was 
probably  much  squabbling  around  the  platter  of 
subsistence,  a  keen  and  literal  struggle,  and  it 
may  be  that  we  owe  much  to  the  natural  selection 
of  those  ancient  days.  But  as  age  succeeded 
age,  and  man's  brain  developed,  he  cared  less 
and  less  for  what  serpent  or  thorn  or  flood  could 
do ;  his  struggle  for  existence  changed  in  tone 
and  colour.  And  nowadays,  except  in  the  out- 
skirts of  civilisation,  there  are  few  wild  beasts 
that  worry  man  much,  the  serpent  that  bites 
his  heel  is  usually  more  or  less  microscopic, 
every  year  increases  his  mastery  over  physical 
forces,  and  he  is  extending  his  kingdom  to  the 
heavens. 

All  through  the  ages  there  has  been  a  winnowing 
by  disease  and  famine,  still  very  marked  in  certain 
peoples,  and  to  this  also,  as  regards  some  of  our 
qualities,  we  have  probably  owed  much.  Of  the 
primaeval  crudity  of  the  struggle  for  existence, 
to  which  sections  of  mankind  are  sometimes 
forced  back,  we  get  occasional  appalling  glimpses  ; 
for  instance,  when  a  panic  unmans  men  altogether. 
But  every  one  knows  that  we  do  all  that  in  us 
lies  to  put  a  stop  to  elimination  by  disease  and 
famine.  Partly  through  genuine  sympathy,  partly 


214        DARWINISM    AND    HUMAN    LIFE 

from  a  desire  to  avoid  unpleasantness,  we  insist 
on  keeping  the  unfit  alive. 

As  the  struggle  with  physical  forces  and  with 
wild  beasts  became  easier,  with  more  frequent 
breathing-times  and  with  more  encouragement  to 
self-assertiveness,  there  came  to  be  more  com- 
petition between  fellows,  and  it  may  be  that  we 
owe  much  to  the  deadly  inter-tribal  wars  of  ancient 
times,  which  would  tend  to  favour  not  only  strength 
but  solidarity.  The  conflict  of  races  still  continues 
among  civilised  peoples,  in  trade  as  much  as  in 
war ;  and,  if  there  must  be  this  conflict,  it  is  to 
be  desired  that,  as  the  result  of  it,  there  may  be 
"  mastery  for  the  foreseeing  nation,  for  the  nation 
with  the  cleaner  bill  of  health,  the  more  united 
purpose  of  all  classes,  and  the  sounder  intellectual 
equipment  of  its  units."1  It  is  impossible  to 
ignore,  however,  that  the  whole  aspect  has  changed 
in  modern  times,  and  that  the  issues  are  less 
clear.  We  cannot  trust  to  the  selective  process 
with  equanimity.  It  is  obvious,  for  instance, 
that  the  issue  of  the  conflict  often  depends  very 
largely  on  length  of  purse  and  up-to-date-ness  of 
equipment,  and  only  to  a  slight  extent  on  the 
organic  qualities  of  the  race  or  people. 

CONTRAST  BETWEEN  THE  HUMAN  KACE  AND  THE 
ANIMAL  WORLD. — It  is  not  necessary  to  spend 
time  in  showing  at  length  that  the  venue  changes 
greatly  when  we  pass  from  the  animal  world  to 
the  human  race.  Apart  from  the  social  feelings 
which  make  the  cruder  forms  of  natural  selection 
intolerable,  there  are  many  complicating  factors. 

(1)  Animals  have  very  little  power  outside  their 

1  "  The  Scope  and  Importance  to  the  State  of  the  Science  of 
National  Eugenics,"  by  Karl  Pearson.  London,  1909. 


SELECTION:     ORGANIC   AND    SOCIAL   215 

own  constitution  of  strengthening  their  position 
in  the  struggle  for  existence,  but  man  has  much. 
He  gets  to  himself  appliances  and  instruments, 
engines  and  machines,  and  the  dwarf  bends  the 
Titan  to  his  will. 

(2)  If  a  number  of  unsociable  men  were  ship- 
wrecked on  a  Kobinson  Crusoe  island  and  lived 
each  for  himself,  a  more  or  less  natural  selection 
might  occur.     In  human  societary  forms,  however, 
there  is  so  much  division  of  labour  that,  all  social 
sentiment  apart,  many  get  a  chance  whom  Nature 
would  not  tolerate.    As  a  simple  illustration,   we 
may  note  that  the  extremely  short-sighted  are 
by  no  means  excluded  from  having  a  successful 
career.    Even  short-sighted  dogs  and  horses  sur- 
vive   in    domestication.     But  in  wild    nature    a 
short-sighted  vulture  must  perish ;  it  cannot  get 
spectacles. 

(3)  Most  animals  have  to  get  their  own  food 
directly  ;  we  cite  as  great  rarities  cases  like  that 
of   the   slave-keeping   ants,    who   not   only  have 
their  food  collected  but  have  literally  to  be  fed 
by  their  minions.     But  in  mankind  the  majority 
get  their  bread  and  butter  in  exchange  for  some- 
thing else.     Thus  types  that  could  not  survive 
in  open  nature  flourish  bravely. 

(4)  Most  animals  have  no  inheritance  outside 
of  themselves,  but  in  mankind  there  are  many 
kinds  of  external  legacies.     It  is  only  in  a  very 
literal  sense  that  the  millionaire's  son  can  say, 
"  Naked  came  I  forth,"  and  an  inherited  title 
may  save  a  man  in  the  social  struggle  for  existence 
when  neither  his  body  nor  his  brains  could  avail. 

SOME   NATURAL   SELECTION    REMAINS. — While 
much  of  the  selection  that  takes  place  in  human 


216       DARWINISM   AND   HUMAN   LIFE 

society  is  very  different  from  natural  selection, 
and  while  we  systematically  thwart  the  process 
of  natural  selection,  some  still  persists  in  present 
operation.  Let  us  get  a  hold  of  Prof.  Karl 
Pearson's  argument.  If  Darwinism  applies  to 
man,  "we  must  have  evidence  (1)  that  man 
varies,  (2)  that  these  variations,  favourable  or 
unfavourable,  are  inherited,  and  (3)  that  they 
are  selected."  (1)  "  The  extent  of  variation  in 
both  man  and  woman  has  been  measured  by  the 
Biometric  School  in  nearly  two  hundred  cases." 
(2)  "  There  appears  no  doubt  that  good  and 
bad  physique,  the  liability  to  and  the  immunity 
from  disease,  the  moral  characters  and  the  mental 
temperament,  are  inherited  in  man  and  with 
much  the  same  intensity."  (3)  Careful  work  has 
shown  that  the  death-rate  in  man  is  partly  selective 
— a  function  of  his  constitution.  But  while  there 
is  still  some  natural  selection  left  at  work,  it 
has  diminished  out  of  all  proportion  to  the  need 
for  it.  "  Consciously  or  unconsciously,  we  have 
suspended  the  racial  purgation  maintained  in  less 
developed  communities  by  natural  selection." 

Sir  Ray  Lankester  has  pointed  out  that  the 
ceaseless  increase  of  man  is  absolutely  peculiar 
to  him  of  all  living  species,  animal  or  vegetable, 
and  this  is,  as  Saleeby  says,  "  the  source  of  the 
major  facts  of  history  and  the  besetting  condition 
of  every  social  problem  that  can  be  named  at 
this  hour."  Man's  persistent  increase  is  the  more 
remarkable  since  he  is  well  known  to  be  a  slowly 
reproducing  animal — slowest  perhaps,  except  a 
few  extreme  cases  like  the  elephant.  The  point 
is  this,  that  whereas  most  animals  have  a  much 
higher  birth-rate  than  man,  there  is  none  with 


SELECTION:     ORGANIC   AND    SOCIAL   217 

such  a  low  death-rate.  The  meaning  of  this  is 
that  man  has  thrown  off  the  natural  selection 
bondage,  and  insists  on  saying,  and  saying  success- 
fully, "I  will  live,"  when  every  natural  chance 
is  against  him.1 

THE  DILEMMA  OF  CIVILISATION. — The  whole 
trend  of  evolution  since  civilisation  began  has 
been  to  throw  off  the  yoke  of  natural  selection, 
and  we  are  thus  brought  face  to  face  with  a  for- 
midable dilemma.  It  is  impossible  to  return  to  a 
natural  selection  regime,  and  yet  we  have  not 
been  able  to  put  an  equally  effective  social  selection 
into  operation.  No  one  has  stated  the  dilemma 
more  clearly  than  Herbert  Spencer :  "  The  law 
that  each  creature  shall  take  the  benefits  and 
the  evils  of  its  own  nature  has  been  the  law  under 
which  life  has  evolved  thus  far.  Any  arrangements 
which,  in  a  considerable  degree,  prevent  superiority 
from  profiting  by  the  rewards  of  superiority,  or 
shield  inferiority  from  the  evils  it  entails — any 
arrangements  which  tend  to  make  it  as  well  to  be 
inferior  as  to  be  superior,  are  arrangements  dia- 
metrically opposed  to  the  progress  of  organisation, 
and  the  reaching  of  a  higher  life." 

THE  EXTREME  "  LAISSEZ-FAIRE  "  POSITION. — In 
face  of  this  dilemma  various  suggestions  have  been 
made.  The  first  is  that  we  should  try  to  restrict 
our  kindness — a  kindness  which  the  future  may 
call  cruelty.  Plato,  in  his  "  Laws,"  recognised  the 
value  of  the  "  purgation  of  the  State  "  which  was 
effected  automatically  by  a  stern  struggle  for 
existence  ;  and  to  an  interference  with  natural 
selection,  it  is  said,  much  of  our  sea  of  troubles  is 

1  See  "  The  Kingdom  of  Man,"  by  Sir  E.  Ray  Lankester.  (London, 
1906.) 


218       DARWINISM   AND    HUMAN   LIFE 

due.  Can  we  not  return,  then,  in  some  measure 
to  the  old  regime  ?  Should  we  not  be  more 
guarded  in  our  interference  with  natural  elimination, 
e.q.  in  preventing  the  elimination  of  weaklings  and 
wasters  whose  survival  and  propagation  cannot  but 
be  a  drag  on  the  race  ? 

This  suggestion  is  open  to  many  objections.  In 
the  first  place,  there  is  the  general  answer  that,  as 
civilisation  has  involved  continuous  interference 
with  natural  selection,  there  is  danger  in  the 
proposal  to  pursue  directly  opposite  tactics.  In 
the  second  place,  the  theoretical  suggestion  to 
return  to  the  old  natural  selection  regime  is  not 
practicable,  partly  because  of  the  complexity  of 
our  social  organisation,  which  offers  so  many 
niches  of  opportunity  to  weaklings  and  wasters, 
and  partly  because,  without  a  great  change  in  social 
sentiment,  it  is  in  civilised  communities  quite 
impossible  not  to  try  to  save  those  to  whom 
Nature  would  show  no  mercy.  It  is  likely  that 
we  are  often  cruel  in  our  charity,  but  we  cannot 
altogether  help  it. 

Besides  these  general  objections  to  the  extreme 
laissez-faire  position,  there  are  many  particular 
objections.  Let  us  take,  for  instance,  the  sugges- 
tion that  we  should  cease  supporting  hospitals  and 
the  like. 

(1)  Our  attempt  to   lessen   an   artificially  ex- 
aggerated infantile  mortality  cannot  be  accurately 
described    as   an   interference  with   the  order  of 
nature  ! 

(2)  Much  weakness  which  we  try  to  strengthen 
is  only  superficially,  not  organically  weak ;  and 
while  we  keep  alive  some  who  are  rotten  we  save 
many  who  only  require  temporary  shelter.     One 


SELECTION:     ORGANIC   AND    SOCIAL   219 

enthusiast  over  bacterial  selection  says  :  "  The 
higher  the  infantile  mortality  which  medicine  so 
energetically  combats,  the  surer  is  the  next 
generation  of  being  purged  of  all  weak  and  sickly 
organisms."  But  he  forgets  that  the  infantile 
maladies  also  affect  the  intrinsically  strong  and 
capable,  and  often  weaken  them,  one  might  say, 
quite  gratuitously. 

(3)  Many  of  the  microbes  which  thin  our  ranks 
are  very  indiscriminate:  they  remove  the  wrong 
people.  Prof.  Berry  Haycraft,  in  his  "  Darwinism 
and  Race  Progress,"  points  out  that  the  hygienists, 
in  warring  against  microbes,  are  eliminating  the 
eliminators  who  have  made  our  race  what  it  is. 
This  is  a  very  doubtful  thesis;  but,  even  if  it 
were  true,  it  is  open  to  us,  as  the  author  of 
course  recognises,  to  put  other  modes  of  selection 
into  operation.  Can  man  not  select  better  than 
bacteria  ? 

SOCIAL  SURGERY. — A  second  suggestion,  which 
goes  a  step  further  than  the  first,  is  that  we  should 
take  more  thought  for  the  morrow  by  deliberately 
pruning  our  stock  of  its  diseased  buds,  especially 
of  those  who,  if  they  survive,  will  be  miserable 
themselves  and  a  cause  of  misery  to  others. 

Nietsche  had  the  courage  to  say  what  many  feel, 
that  it  would  be  a  kindness  to  suppress  a  good  many 
of  us.  There  is  no  doubt  about  that,  but  would 
it  be  a  permissible  kindness  ?  Who  is  sufficient 
for  these  things  ?  It  is  one  thing  to  discourage 
in  every  feasible  way — compatible  with  rational 
social  sentiment — the  breeding  of  weaklings  by 
weaklings ;  it  is  another  thing  to  look  a  fellow 
creature  in  the  eyes  and  say,  "  You  must  die." 
Remove  weaklings,  forsooth !  read  over  the  roll  of 


220       DARWINISM    AND    HUMAN    LIFE 

them  first ;  might  they  not  say,  "  Yet  we  are 
the  movers  and  shakers  of  the  world  for  ever,  it 
seems  "  ? 

Perhaps  the  time  may  come  when  the  noblest 
social  sentiment  and  a  maturer  science  will  agree 
that  this  bud  and  that  should  not  be  allowed  to 
open ;  but  the  time  is  not  yet.  The  biologist  dis- 
trusts social  surgery  because  of  his  ignorance ; 
the  sociologist  rejects  it  because  the  thought  of  it 
makes  the  foundations  of  society  tremble,  and 
because  the  social  ideal  of  good  citizens  is  wider 
than  the  ideal  of  good  physique  ;  and  the  practical 
man  will  not  hear  of  it  because  he  knows  that  it 
is  not  in  us  to  practise  it.  Even  if  the  way 
were  clear,  it  would  be  like  destroying  fruits  and 
leaving  roots,  and  securing  a  fictitious  comfort  by 
an  entirely  artificial  method  of  disowning  our 
social  liabilities. 

Is  SOCIAL  SELECTION  COMPENSATING  FOR  THE 
DIMINUTION  OF  NATURAL  SELECTION  ? — A  third 
suggestion  leads  us  nearer  practicable  tactics,  for 
it  raises  an  inquiry  into  the  modes  of  selection 
which  are  at  present  in  operation  in  human  societies. 
How  do  these  compare  with  natural  selection,  and 
how  far  can  they  be  trusted  to  effect  the  purgation 
of  the  State  ? 

Whatever  form  natural  selection  may  take — 
and  it  has  a  thousand — this  is  always  true  about 
it,  that  the  eliminated  are  eliminated  because  of 
some  defect  in  or  pertaining  to  them,  "  the  unlit 
lamp  and  the  ungirt  loin  "  in  some  form,  and  that 
the  survivors  survive  because  of  some  relatively 
advantageous  quality  in  or  pertaining  to  them. 
But  there  are  many  selective  processes  in  human 
society  which  depend  on  something  else  than  the 


SELECTION:    ORGANIC   AND   SOCIAL    221 

inherent  bodily  or  mental  quality  of  those  selected. 
Let  us  consider  some  illustrations  of  these. 

A  German  Professor,  writing  of  the  enormous 
mortality  of  children  in  large  towns,  says  that  all 
those  young  lives  must  pass  out  because  there  is 
no  place  laid  for  them  at  Nature's  great  table : 
"  Natural  selection,  don't  you  know/5  But  the 
hideous  mortality  in  question  has  almost  nothing 
to  do  with  Nature's  great  table  or  with  natural 
selection.  How  can  one  tell  ?  The  statistics  show, 
to  some  extent,  what  the  children  die  of,  and  it  is, 
to  a  large  extent,  of  their  parents  !  For  some 
large  towns  the  deaths  of  infants  have  been  care- 
fully classified,  not  only  as  to  the  cause  of  death, 
but  in  reference  to  what  the  parents  do  or  do  not 
do ;  the  mortality  is  double  in  some  classes  what  it 
is  in  others ;  and  this  seems  certain,  that  in  many 
cases  the  selection  is  not  related  to  the  physique 
of  those  eliminated.  The  selection  depends,  in 
great  part,  on  the  parental  standard  of  comfort  and 
standard  of  character. 

But,  it  may  be  said,  if  there  is  a  differential  death- 
rate,  a  larger  infant-mortality  in  the  less  thrifty 
families,  will  that  not  work  out  right  in  the  long 
run,  since  their  elimination  implies  a  sifting  out  of 
the  hereditarily  thriftless  types  ?  The  answer  is 
that,  along  with  the  greater  mortality,  there  is 
associated  a  greater  fecundity,  so  that  the  sifting 
is  partially  counteracted  ;  moreover,  it  is  not  to 
be  supposed  that  the  less  thrifty  families  with  high 
infant  mortality  are  to  be  thought  of  as  necessarily 
undesirables ;  much  of  the  thriftlessness  is  as 
artificial  as  much  of  the  mortality  is  unnecessary. 

Take  another  instance,  which  may  serve  to  bring 
out  the  difference  in  method  and  results  between 


222       DARWINISM   AND    HUMAN    LIFE 

social  selection  and  natural  selection.  In  some 
countries  there  are  posts  as  foresters  and  police 
which  are  rilled  by  picked  men,  often  by  very 
desirable  types  physically,  mentally,  and  morally. 
Here,  then,  is  the  setting  up  of  a  standard  and  a 
rejection  of  the  unfit ;  and,  of  course,  it  works  in  the 
right  direction.  But  it  is  easy  to  see  that  it  differs 
from  what  goes  on  in  nature,  and  that  the  issues  are 
complicated.  For  instance,  as  a  German  writer 
points  out,  the  ineligible  were  also  ineligible  for 
military  service.  There  are  no  disadvantageous 
consequences  of  this;  the  rejected  are  spared  time 
and  money,  they  can  marry  earlier,  and  so  on. 

The  stress  of  competition  exercises  a  certain 
selective  influence,  but  how  differently  it  works 
from  natural  selection !  It  does  not  necessarily 
make  for  the  elimination  of  the  unsuccessful;  it 
shifts  him.  It  may  compel  him  into  an  occupation 
where  his  chances  of  death  are  lessened.  If  he  is 
driven  out  of  regular  employment  altogether,  he 
passes  into  ranks  with  a  high  death-rate,  but  even 
then  natural  selection  does  not  work,  for  he  usually 
has  a  large  family  in  the  meantime.  Thus  we  see 
that  many  processes  of  differential  elimination  in 
human  societies  turn  out,  on  close  inspection,  to 
be  very  different  from  natural  selection,  and  this 
is  our  whole  point  at  present — that  these  processes 
of  social  selection  cannot  be  trusted,  and  that 
nothing  is  more  absurd  than  to  murmur  "  Survival 
of  the  fittest  " — since  that  is  precisely  what  is  not 
happening  either  in  the  Darwinian  sense  or  in  any 
other. 

EEVERSED  SELECTION  IN  HUMAN  SOCIETY. — 
Those  who  are  unfamiliar  with  the  biological  point 
of  view  seem  to  find  it  difficult  to  bear  in  mind 


SELECTION:     ORGANIC   AND    SOCIAL   223 

that  organisms  may  evolve  "  downwards  "  as  well 
as  "  upwards  "  in  becoming  fitter  to  given  con- 
ditions. By  "  upwards  "  is  meant  in  the  direction 
of  a  more  differentiated  and  integrated  organisa- 
tion— a  more  complex  and  controlled  constitution — 
and  we  have  a  habit  of  regarding  ourselves  as  being 
very  much  "  up/'  Now,  while  it  is  true  that  the 
general  trend  of  evolution  throughout  the  ages  has 
been  "  upwards,"  we  must  not  forget  that  the 
tapeworm  has  been  evolved  as  truly  as  the  golden 
eagle,  the  one  in  a  dark  bypath,  the  other  on  the 
mountain-tops,  both  well  adapted  to  their  con- 
ditions of  life. 

The  term  "  reversed  selection  "  has  been  applied 
to  cases  where,  under  altered  conditions,  organisms 
seem  to  have  gone  "  downwards,"  but  the  term  is 
unfortunate.  If  by  selection  a  race  is  becoming 
better  adapted  to  the  conditions  of  its  life,  it  is 
to  the  cold-blooded  scientific  onlooker  immaterial 
whether  the  direction  of  the  race-movement  is 
up  or  down.  It  is  evolution  all  the  same.  Con- 
sidering the  movement  in  relation  to  a  standard, 
however,  we  may  say  that  some  selective  pro- 
cesses make  for  progress  along  the  lines  which 
have  marked  the  general  trend  of  evolution — 
greater  complexity,  greater  control,  a  fuller,  freer 
life — and  that  other  selective  processes  make  for 
change  in  the  opposite  direction. 

Our  question  now  is,  are  there  in  human  society 
selective  processes  at  work  which  make  for  de- 
generacy ?  We  all  know  the  difficulty  of  answering 
this  question,  because  social  processes  are  so  com- 
plex and  many-sided.  Even  when  the  social 
selection  is  in  part  wrong  we  cannot  always  stop 
it.  Civilisation  is  a  long-drawn-out  compromise. 


224       DARWINISM   AND    HUMAN   LIFE 

In  illustration,  let  us  briefly  consider  the  bio- 
logical aspect  of  prolonged  wars.  In  his  "  Human 
Harvest "  President  Jordan  tells  of  a  man  more 
strenuous  than  wise,  who  possessed  a  stud  of 
horses,  which  he  would  make  more  strong  and  fleet. 
"  So  he  rode  them  swiftly  with  all  his  might, 
day  and  night,  always  on  the  course,  always 
pushed  to  the  utmost,  leaving  only  the  dull  and 
sluggish  to  remain  in  the  stalls.  For  it  was  his 
dream  to  fill  these  horses  with  the  spirit  of  action, 
with  the  glory  of  swift  motion,  that  this  glory 
might  be  carried  on  and  on  to  the  last  generation 
of  horses.  There  were  some  who  could  not  keep 
the  pace,  and  to  these,  and  these  alone,  he  assigned 
the  burden  of  bearing  colts.  And  the  feeble  and 
broken,  the  dull  of  wit,  the  coarse  of  limb,  became 
each  year  the  mothers  of  the  colts.  .  .  .  For  a 
time  whip  and  spur  made  good  the  lack  of  native 
movement  .  .  . ;  but  the  current  of  life  ran  steadily 
downward.  Each  generation  yielded  weaker  colts, 
rougher,  duller,  clumsier  colts,  and  no  amount  of 
training  or  lash  or  spur  made  any  permanent 
difference  for  the  better.  The  horse-harvest  was 
bad.  Thoroughbred  and  race-horse  gave  place 
to  common  beasts,  for  in  the  removal  of  the  noble 
the  ignoble  always  finds  its  opportunity.  It  is 
always  the  horse  that  remains  which  determines 
the  future  of  the  stud.  In  like  fashion,  from  the 
man  who  is  left  flows  the  current  of  human  history." 

Let  us  observe  how  Jordan  works  out  his  thesis 
in  relation  to  man.  "  In  the  conquests  of  Rome, 
Vir,  the  real  man,  went  forth  to  battle  and  to  the 
work  of  foreign  invasion  ;  Homo,  the  human  being, 
remained  in  the  farm  and  the  workshop  and  begat 
the  new  generation/'  Prof.  Seeck,  one  of  the 


SELECTION:     ORGANIC   AND   SOCIAL   225 

historians  of  the  downfall  of  the  ancient  world, 
says  that  it  was  due  mainly  to  "  the  rooting  out  of 
the  best/'  "  Only  cowards  remained,  and  from 
their  brood  came  forward  the  new  generations." 
"  Wars  are  not  paid  for  in  war  times,"  Franklin 
said ;  "  the  bill  comes  later."  "  The  Roman 
Empire,"  says  Seeley,  "  perished  for  want  of  men." 
There  were  plenty  of  people — "  people  with  too 
much  guano  in  their  composition,"  as  Emerson 
said ;  but  even  Julius  Caesar  noted  that  men  were 
becoming  terribly  scarce.  Prof.  Bury  writes :  "  The 
effect  of  the  wars  was  that  the  ranks  of  the  small 
farmers  were  decimated,  while  the  number  of 
slaves  who  did  not  serve  in  the  army  multiplied." 
The  German  historian  goes  on  :  "  Out  of  every 
hundred  thousand  strong  men,  eighty  thousand 
were  slain.  Out  of  every  hundred  thousand 
weaklings,  ninety  to  ninety-five  thousand  were 
left  to  survive." 

But  all  that  was  long  ago.  So  we  take  up 
Jordan's  "  Human  Harvest "  again,  and  turn  to 
France — to  France,  ever  young  and  splendid  in 
spirit.  But  the  birth-rate  continues  steadily  to 
fall ;  the  average  stature  is  lower  by  two  inches 
than  it  was  a  century  ago  ;  and,  as  with  ourselves, 
there  are  other  disquieting  symptoms.  These  are 
doubtless  due  to  a  variety  of  co-operating  causes, 
but  can  we  exclude  what  one  of  themselves  has 
said,  that  "  it  will  take  long  periods  of  peace  and 
plenty  before  France  can  recover  the  tall  statures 
mowed  down  in  the  wars  of  the  republic  and  the 
first  empire  "  ? 

Year  after  year  Napoleon  seized  the  youth  of 
good  stature,  and  left  their  bones  in  great  heaps 
throughout  Europe.  "  You  can  always  fill  the 

15 


226       DARWINISM   AND   HUMAN    LIFE 

places  of  soldiers/'  he  said ;  but  he  had  eventually 
to  be  content  with  boys.  "  The  mighty  swirl  of 
the  Moscow  campaign  sucked  in  150,000  lads  of 
under  twenty  years  of  age  into  the  devouring 
vortex  "  ;  out  of  600,000  who  crossed  the  Niemen 
to  conquer  Russia,  20,000  famished,  frost-bitten 
spectres  staggered  back.  It  was  the  rapid  suc- 
cession of  skimmings  that  told.  "  In  less  than 
half  a  year  after  the  loss  of  half  a  million  men  a 
new  army,  nearly  as  numerous,  was  forthcoming 
and  the  grim  roll-call  of  wasted  men,  many  of 
them  wasted  heroes — about  half  of  whom  were 
French — amounted,  according  to  some,  to  three 
millions."  It  is  true  that  glorious  France  survived 
all  this  bleeding,  but  how  impoverished,  qualita- 
tively as  well  as  quantitatively !  and  even  a  great 
life-saver  like  Pasteur  could  not  restore  the  cubit 
of  stature  which  the  great  life-destroyer  had 
lopped  off.1 

We  admit  that  wars  have  been  necessary  and 
righteous — especially  necessary — and  that  they 
may  be  so  still,  but  this  opinion  does  not  affect  the 
fact  that  prolonged  war  in  which  a  nation  takes 
part  is  bound  to  impoverish  the  breed,  since  the 
character  of  the  breed  always  depends  on  the  men 
who  are  left.  How  else  can  we  understand  what 
has  happened  so  often,  that  an  older  civilisation 

1  While  I  plead  guilty  to  disbelief  in  the  biological  value  of 
modern  war,  I  do  not  think  this  is  inconsistent  with  an  appreciation 
of  the  soldier's  qualities.  Who  does  not  admire  what  Mr.  Sandeman 
describes  in  his  "  Uncle  Gregory  "  ?  (1909)  ..."  That  quite  un- 
mistakable note  that  you  get  in  a  very  few  people  who,  in  one  way 
or  another,  have  actually  accepted  death,  and  are  only,  so  to  speak, 
alive  in  the  meantime.  It  belongs  to  the  flawless  perfection  of  the 
military  spirit,  with  its  entire  detachment  from  life  itself,  from  self- 
will,  from,  fear,  and  from  ease,  and  from  all  pretences." 


SELECTION:    ORGANIC   AND   SOCIAL   227 

is  overthrown  by  another  less  evolved  ?  The  only 
thing  a  nation  dies  of  is  lack  of  men :  and  is 
there  not  disquieting  evidence  of  the  increase  of 
incapables  ?  It  is  said  that  we  cannot  relax  one 
spine  of  our  national  belligerence,  since  we  must, 
at  all  costs,  uphold  our  national  supremacy,  having 
all  these  teeming  millions  to  feed.  But  is  this  not, 
in  part  at  least,  a  vicious  circle  ?  The  question 
arises  whether  it  is  not  in  great  part  preoccupation 
with  militarism  that  is  responsible  for  keeping  up 
our  national  misery.  With  a  little  money  saved 
off  belligerence,  what  might  not  be  done  towards 
social  improvement ! 

An  end,  then,  to  the  courage  and  the  daring  and 
the  chivalry  which  war  has  ever  kept  alive  !  But 
can  any  one  seriously  believe  this  ?  The  story  of 
the  exploration  and  conquest  of  earth  and  sea  is 
full  of  heroes,  whose  work  was  constructive,  not 
destructive.  The  man  who  has  grit  enough  to 
bring  about  the  afforestation  or  the  irrigation  of 
a  country  is  not  less  worthy  of  honour  than  its 
conqueror. 

SUMMARY  OF  THE 'ARGUMENT. — In  early  days 
there  was  a  keen  struggle  for  existence  with  the 
forces  of  nature,  with  wild  beasts,  and  between 
fellow-men.  There  was  much  natural  selection. 
Gradually  the  venue  changed,  there  has  been  a 
persistent  emancipation  from  the  yoke  of  natural 
selection,  and  among  civilised  peoples  it  has  now 
but  little  sway.  This  exposes  our  race  to  the 
gravest  risks  of  retrogression.  To  obviate  this, 
some  suggest  that  we  should  return  in  part  to  the 
old  regime ;  other  advise  the  practice  of  some 
social  surgery ;  but  neither  of  these  suggestions  is 
feasible — for  general  tactics  at  least.  It  is  also 


228       DARWINISM   AND    HUMAN    LIFE 

suggested  that  there  are  many  forms  of  social 
selection  in  operation  which  take  the  place  of 
natural  selection ;  but  inquiry — here  very  super- 
ficial— shows  that  these  forms  of  social  selection 
do  not  work  out  as  natural  selection  does,  and 
that  some  of  them  have  results  which  are,  from 
the  biological  point  of  view,  retrogressive. 

CONSTRUCTIVE  SUGGESTIONS. — As  we  are  here 
mainly  concerned  with  getting  the  biology  of  the 
problem  clear,  we  cannot  do  more  than  hint  at 
the  general  policy  of  betterment.  In  general, 
it  cannot  be  other  than  this — to  adhere  to  and 
increase  those  forms  of  selection  which  make  for 
the  survival  of  beautiful  and  healthful  surround- 
ings, educative  and  wholesome  occupations,  sane 
and  progressive  men  and  women.  The  first  ideal 
has  been  called  that  of  Eutopias,  the  second  that 
of  Eutechnics,  the  third  that  of  Eugenics.1  They 
obviously  correspond  to  the  three  fundamental 
categories  of  biology :  Environment,  Function, 
and  Organism. 

SELECTION  OF  EUTOPIAS. — Possessed  by  certain 
enthusiasms  or  illusions,  a  man  may  gladly  live — 
and  perhaps  more  gladly  die — on  a  cinder-heap ; 
and  there  is  a  local  patriotism  which  throws  a 
halo  round  any  home.  But  deep  down  in  every 
healthy  human  being,  rooted  perhaps  in  a  once 
closer  contact  with  nature,  there  is  a  love  of 
the  fresh  air,  the  clean  earth,  the  running  brook, 
the  waving  trees,  the  singing  birds — a  beautiful 
place,  in  short,  such  as  even  a  garden  city  might 
afford. 

The  biological  importance  of  living  in  beautiful 

1  The  first  two  by  Prof.  Patrick  Geddes,  the  third  by  Sir  Francia 
Gallon. 


SELECTION:     ORGANIC   AND   SOCIAL   229 

surroundings  is  inestimable.  It  makes  for  health 
of  body  and  brain  ;  it  awakens  long-dormant  buds  ; 
it  fills  up  the  life  with  wholesome  delights ;  it  pro- 
duces pleasant  modifications  on  the  individual ;  and 
who  can  tell  how  its  potent  messages  may  travel 
by  "  the  wireless  telegraphy  of  ante-natal  life  "  ? 

All  this  is  familiar,  yet  are  we  not  slow  to  adopt 
a  resolute  policy  of  securing  one  of  the  really  good 
things  in  life — a  Eutopia  ?  Every  one  knows  that 
this  is  no  Utopia,  if  we  can  only  make  up  our 
minds  to  live  more  in  the  present  and  less  in  the 
future. 

SELECTION  OF  HEALTHFUL  OCCUPATIONS. — With- 
in the  hands  of  all  men  of  good-will  there  is 
a  powerful  instrument  of  progress,  technically 
known  as  "  the  criticism  of  consumption."  It  is 
one  of  the  most  effective  factors  in  amelioration, 
especially  as  regards  the  selection  of  healthful 
occupations.  Perhaps  more  might  be  made  of  it 
if  the  strategy  involved  was  more  generally  recog- 
nised. When  we  discover  that  certain  articles 
are  socially  injurious,  bad  for  the  maker,  bad  for 
the  buyer,  we  should  not  buy  them,  but  get  instead 
something  which  it  was  good  for  a  man  to  make, 
and  good  for  us  to  have.  Now,  if  we  do  this 
consistently  and  keep  at  it  unwaveringly,  and 
get  others  to  do  the  same,  we  will,  if  we  keep 
the  selection  a-going  long  enough,  often  enough, 
stringently  enough,  put  an  end  to  an  ugly  article 
and  an  injurious  occupation.  The  process  is  never 
quick  enough  to  be  unjust  or  cruel,  as  the  swings 
of  fashion  often  are.  Apply  this  consistent  selec- 
tion to  favouring  wholesome  people,  not  wasters, 
constructive  occupations,  not  destructive  ones, 
beautiful  places,  not  ugly  ones — and  we  have 


230       DARWINISM   AND    HUMAN    LIFE 

returned  to  Nature's  method  on  a  higher  turn  of 
the  spiral.  Even  natural  selection  would  favour 
the  survival  of  qualities  like  healthfulness  ;  it  is 
for  a  rational  social  selection  to  continue  the 
endless  task. 

EUGENIC  SELECTION. — The  third  aspect  of  the 
biological  ideal  towards  which  it  is  necessary  to 
select  is  the  improvement  of  the  human  breed — 
the  ideal  of  eugenics.  There  is  perhaps  no  nobler 
enthusiasm,  and  while  some  of  the  enthusiasts  are 
occasionally  carried  away  by  their  zeal,  we  must 
not  reject  the  quiet  wisdom  of  a  veteran  general 
like  Sir  Francis  Galton,  because  of  the  extravagant 
utterances  of  subalterns.  But,  apart  from  subal- 
terns, it  is  not  easy  for  even  expert  students  pos- 
sessed by  a  worthy  enthusiasm  to  keep  the  complex 
issues  in  perspective.  Illustrations  may  be  found, 
for  instance,  in  the  excellent  exposition  of  the 
eugenist  argument  which  Dr.  Saleeby  has  given  us 
in  his  "Parenthood  and  Race-Culture"  (1909). 
"  The  idea  of  selection  for  parenthood  as  determining 
the  nature,  fate,  and  worth  of  living  races  is  Darwin's 
chief  contribution  to  thought,  and  finds  in  eugenics 
its  supreme  application." 

"  The  question  is  not  whether  a  given  proposal 
is  socialistic,  individualistic,  or  anything  else,  but 
whether  it  is  eugenic.  If  it  is  eugenic,  that  is  final. 
To  this  all  parties  will  come,  and  by  this  all  parties 
will  be  judged.  ...  I  claim  for  eugenics  that  it  is 
the  final  and  only  judge  of  all  proposals,  and 
principles,  however  labelled,  new  or  old,  orthodox 
or  heterodox."  This  is  forcibly  put,  but  it  illus- 
trates the  difficulty  of  appreciating  the  complexity 
of  the  human  situation.  The  'eugenic  ideal  is 
the  breeder's  ideal — vigorous  organisms,  and  the 


SELECTION:    ORGANIC   AND   SOCIAL   231 

eugenist's  method  is  the  breeder's  method — 
selection  for  parenthood;  but  the  difficulty  is  that 
we  have  to  deal  with  larger  ends  than  men,  we 
cannot  ignore  the  social  framework  and  a  whole 
hierarchy  of  social  integrates.  Even  if  we  ignore 
them  in  theory,  they  will  be  too  strong  for  us  in 
practice.  The  eugenic  programme  must  submit 
to  social  criticism,  which  will  not  be  merely 
theoretical. 

Let  us  recall  some  of  the  facts  which  bring  the 
importance  of  the  eugenic  ideal  home  to  us.  One 
quarter  of  the  married  people  of  this  country, 
one-sixth  to  one-eighth  of  the  total  adult  popula- 
tion, Prof.  Karl  Pearson  tells  us,  produce  50  per 
cent,  of  the  next  generation.  "  How  essential  it 
is  for  the  maintenance  of  a  physically  and  mentally 
fit  race  that  this  one-sixth  to  one-eighth  of  our 
population  should  be  drawn  from  the  best,  not  the 
worst  stocks !  "  "  We  cannot  recruit  the  nation 
from  its  inferior  stocks  without  deteriorating  our 
national  character."  This  is  the  argument  which 
Pearson  so  powerfully  develops. 

Of  course  the  statistics  of  diminishing  birth-rate 
require  careful  treatment  by  experts.  The  average 
annual  birth-rate  per  1,000  has  fallen  from  35*35 
in  1876-80  to  28-10  in  1901-1905,  but  against  this 
we  must  notice  that  the  death-rate  has  also  fallen 
from  20*79  to  16.  The  ominous  fact  is  that  it 
was  by  a  gradual  but  persistent  diminution  of 
natality  that  France  reached  her  present  state  of 
a  death-rate  in  excess  of  the  birth-rate. 

Yet  Prof.  Pearson's  point  is  not  so  much  the 
general  diminution,  but  the  differential  diminution. 
In  Britain  the  diminution  seems  greatest  where 
it  is  least  wanted,  namely,  among  the  workers  of 


232       DARWINISM   AND    HUMAN   LIFE 

the  community  and  among  the  more  far-seeing 
and  provident  classes.  French  statistics  show 
that  the  birth-rate  is  less  in  proportion  to  the 
standard  of  comfort.  At  present  the  birth-rate  in 
France  is  said  to  be  below  the  death-rate  in  all 
sections  except  manufacturing  centres.  Among 
academically  educated  Americans  the  average 
number  of  offspring  is  less  than  two. 

There  seems  no  doubt  as  to  the  ominously  rapid 
multiplication  of  the  relatively  unfit.  "  Degener- 
ate stocks  under  present  social  conditions  are  not 
short-lived ;  they  live  to  have  more  than  the  normal 
size  of  family/'  They  have  at  present  a  better 
chance  to  survive  and  multiply  than  ever  before. 
Especially  in  Britain  do  the  weeds  spread  quicker 
than  the  flowers.  The  feeble-minded  are  prolific ; 
certain  kinds  of  degenerates  are  prolific ;  the 
thriftless  are  prolific.  From  a  study  of  150  de- 
generate families,  Dr.  Tredgold  found  that  the 
average  number  of  children  in  a  family  was  7'3, 
not  including  those  still-born,  instead  of  the  normal 
average  of  four. 

Let  us  be  as  generous  as  we  can.  An  unpro- 
mising bud  may  burst  into  a  fine  flower :  John 
Bunyan's  father  was  a  tinker.  But  every  one  is 
agreed  that  there  should  be  no  breeding  from 
epileptics,  lunatics,  paralytics ;  should  not  this 
list  be  added  to  ? l  Is  it  not  a  pity,  for  instance, 

1  In  his  Robert  Boyle  Lecture  on  "  The  Scope  and  Importance 
to  the  State  of  the  Science  of  National  Eugenics  "  (2nd  ed.,  1909) 
Prof.  Karl  Pearson  says :  "  If  we  realise  the  antinomy  which 
Eugenics  brings  to  our  notice  between  high  civilisation  and  racial 
purgation,  we  ask :  How  can  the  dominant  fertility  of  the  fitter 
social  stocks  be  maintained  when  natural  selection  has  been  sus- 
pended ?  I  do  not  think  any  wise  man  would  be  prepared  with  a 
full  answer  to  this  question  to-day.  There  i.-i  i}0  sovereign  remedy 


SELECTION:     ORGANIC   AND    SOCIAL   233 

that  we  should  look  with  favour  on  the  marriage 
of  deaf-mutes  ?  Let  us  admit  that  many  of  the 
unfit  may  be  only  modificationally  unfit — ill- 
nourished  plants  in  the  crowded  garden — requiring 
only  new  soil.  Many  criminals  are  simply  ana- 
chronisms— people  out  of  time  and  out  of  place — 
who  need,  not  incarceration,  but  transplantation. 
Cure  the  poacher  by  making  him  a  collector.  But 
this  will  not  cover  all. 

Let  us  admit,  too,  that  very  bad  stock — such 
as  the  uncontrolled  alcoholic  type — tends  to  work 
itself  out.  Taints  may  be  swamped,  just  as  ex- 
cellences often  are. 

Prof.  Biffen  has  bred  into  a  good  stock  of 
corn  the  quality  of  immunity  to  rust  which  a 
poor  stock  had,  and  perhaps — perhaps — the 
future  has  in  store  for  us  analogous  ways  of 
getting  a  clean  thing  out  of  an  unclean  in  human 
kind. 

Meanwhile,  what  is  to  be  done  ?  Many  gentle 
measures  are  possible — fostering  pride  of  race, 
encouraging  the  marriage  of  desirables,  developing 

for  degeneracy.  Every  method  is  curative  which  tends  to  decrease 
the  fertility  of  the  unfit  and  to  emphasise  that  of  the  fit.  We  may 
find  it  difficult  to  define  the  socially  fit,  although  physique  and 
ability  will  carry  us  far  ;  but  when  we  turn  to  the  habitual  criminal, 
the  professional  tramp,  the  tuberculous,  the  insane,  the  mentally 
defective,  the  alcoholic,  the  diseased  from  birth  or  from  excess, 
there  can  be  little  doubt  of  their  social  unfitness.  Here  every 
remedy  which  tends  to  separate  them  from  the  community,  every 
segregation  which  reduces  their  chances  of  parentage,  is  worthy  of 
consideration.  ...  Is  not  something  more  to  be  insisted  upon  with 
regard  to  the  increase  of  good  stock  ?  .  .  .  A  clean  body,  a  sound 
if  slow  mind,  a  vigorous  and  healthy  stock,  a  numerous  progeny — 
these  factors  were  largely  representative  of  the  typical  Englishman 
of  the  past ;  and  we  see  to-day  that  one  and  all  these  characteristics 
can  be  defended  on  scientific  grounds  ;  they  are  the  essentials  of  an 
imperial  race," 


234       DARWINISM   AND   HUMAN   LIFE 

prejudice  against  the  marriage  of  undesirables, 
fuller  recognition  of  woman's  rights,  both  as  to 
mating  and  maternity.  For  another  step  we  shall 
soon  be  ready — a  form  of  rational  social  selection 
— the  institution  of  a  sort  of  marriage  test  and  some 
attempt  to  prevent  the  multiplication  of  those  who, 
by  their  own  inefficiency,  have  fallen  back  on  the 
community  for  support. 

Social  sentiment  will  not  permit  social  surgery, 
which  is  probably  just  as  well ;  but  we  cannot  be 
proud  of  our  tender-heartedness  when  we  reflect 
on  what  we  do  permit  in  the  way  of  slow  murder 
in  the  present  and  in  the  way  of  keeping  up  misery 
for  the  future. 

In  this  connection  Mr.  Whetham  writes : 
"  When  we  have  built  and  endowed  schools  and 
hospitals,  pulled  down  insanitary  dwellings  and 
thrown  open  green  spaces,  brought  in  fresh  water 
and  uncontaminated  milk,  vaccinated  babies  and 
destroyed  tuberculous  cows,  when  we  have  estab- 
lished a  cult  of  fresh  air,  a  whole  science  of  nature- 
study,  and  the  paraphernalia  of  the  simple  life — 
we  are  brought  up  sharp  against  a  stone  wall.  We 
are  informed  that  our  unemployed  are  chiefly 
unemployable,  that  the  provision  of  more  lunatic 
asylums  is  of  greater  urgency  than  the  provision 
of  increased  school  accommodation,  that  a  whole 
class  of  feeble-minded  individuals  has  grown  up 
and  is  totally  unprovided  for,  that  ability  is  more 
difficult  to  find  and  mediocrity  shows  no  tendency 
to  rise,  that  general  physical  deterioration  may 
be  knocking  at  our  doors — in  short,  in  spite  of  all 
our  efforts,  matters  are  conceivably  worse  than 
when  we  started,  and  an  uncomfortable  feeling 
comes  that  "  in  spite  of "  might  possibly  be  more 


SELECTION:     ORGANIC   AND   SOCIAL   235 

correctly  written  "  on  account  of."  1  Unless  we 
are  prepared  to  do  nothing,  saying  with  Sir  Boyle 
Roche,  "  What  has  posterity  done  for  us  ?  "  then  we 
must  try  "  to  replace  Nature's  selective  death-rate 
by  a  selective  birth-rate."  2  In  any  case,  we  can 
share  in  forming  public  opinion. 

Whymper,  in  his  "  Scrambles  among  the  Alps," 
says  some  forcible  things  about  the  marriage — the 
Church  marriage — of  cretins  who  swarm  in  the 
valley  of  Aosta  and  elsewhere.  For  many  genera- 
tions the  strongest  and  healthiest  peasants  had  to 
go  to  the  wars ;  the  idiotic  and  goitrous  were  left. 
The  disease  may  not  be  in  itself  hereditary,  but 
susceptibility  to  it  is ;  and  in  one  village  it  was 
said  that  all  had  a  goitre  except  the  young  priest. 
In  any  case  the  cretins  of  Aosta  thrive  and  multiply, 
and  the  consummation  of  the  tragedy  is  that  the 
Church  solemnises  their  union.3  At  one  end  we 
have  the  celibacy  of  the  clergy — often  remarkably 
fine  peasant  thinkers  and  dreamers — and  the 
celibacy  of  the  most  gentle  and  spiritual  women — 
a  segregation  from  the  race  of  some  of  its  finest 
types — at  the  other  end  the  blessing  of  the  goitrous 
pair.  Which  things  are  a  parable. 

Some  sneer  at  eugenics  as  obtruding  into  the 
sanctity  of  human  relationships  the  counsels  of 
the  farm-yard;  but  reflection  will  show  that  the 
sanctity  is  heightened,  not  lessened,  when  the 
solemn  issues  are  realised. 

It  is  likewise  quite  certain  that,  whether  we 

1  "  Inheritance  and  Sociology,"  by  W.  C.  D.  Whetham,  in  The 
Nineteenth  Century  and  After  (No.  363,  Jan.  1909),  pp.  74-90. 

2  Saleeby,  "Parenthood  and  Race  Culture"  (1909). 

3  Of  course  one  hopes  it  has  been  changed  in  the  last  few  years. 
It  was  true  quite  lately. 


236       DARWINISM   AND    HUMAN    LIFE 

have  celibate  fellowships  at  the  colleges,  or  adver- 
tise for  a  gardener  "  without  encumbrances,"  or 
dismiss  women  teachers  on  marriage,  or  refrain 
from  marrying  till  we  have  ten  times  the  income 
our  father  had  when  he  begat  us — the  list  can  be 
continued  ad  nauseam — we  are  ignoring  the  funda- 
mental laws  of  good  breeding  or  eugenics,  just  as 
we  are  when  we  refrain  from  condemning  the 
marriage  of  the  feeble-minded  or  from  protesting 
against  certain  charitable  devices  which  create 
more  misery  than  they  relieve. 

By  way  of  illustration,  let  us  think  for  a  moment 
of  China — a  country  of  extraordinary  interest 
to  the  biologist.  It  has  kept  up  a  continuity  of 
state  organisation  and  culture  for  four  thousand 
years  ;  the  people  have  big  brains  and  marvellous 
physique ;  they  are  very  fertile,  the  aristocracy 
not  less  than  the  unlearned  ;  they  have  genuine 
old  families,  going  back  to  Confucius,  and  not 
decadent ;  they  are  in  many  ways  very  moral ; 
and  so  on. 

Now  there  are  many  reasons  for  all  this,  but 
two  strike  the  biologist:  (1)  To  an  extent  quite 
impossible  for  us,  the  Chinese  allow  natural  selec- 
tion in  famine  and  disease,  etc.,  to  go  on  with- 
out hindrance.  Here  we  cannot  imitate  them. 
(2)  For  thousands  of  years,  on  the  other  hand, 
the  Chinese  have  paid  great  attention  to  breeding, 
to  family  histories,  to  family  life,  to  family  feeling, 
and  honour  of  ancestry.  Ages  ago  they  used  to 
send  a  policeman  to  eligible  bachelors  with  a  notice 
to  marry.  In  their  positive  eugenic  practices  the 
Chinese  are  worthy  of  our  imitation. 

And  what  is  the  conclusion  of  all  this  talk  ? 
Nothing  new.  More  and  more  our  human  societies 


SELECTION:    ORGANIC   AND    SOCIAL     237 

free  themselves  from  natural  selection,  and  it 
behoves  us  to  make  sure  that  some  rational 
winnowing  takes  the  place  of  the  automatic 
process  of  nature.  There  are  many  processes  of 
social  selection  going  on,  some  for  evil  and  some 
for  good.  They  require  to  be  sternly  criticised, 
especially  as  those  that  are  for  good  do  not  seem 
to  be  getting  any  grip  of  the  organic  qualities  of 
the  breed. 

We  must  take  more  thought  of  the  improve- 
ment of  our  breed,  not  only  for  its  own  sake — 
for  healthfulness  is  as  fundamental  as  virtue  is 
supreme — but  also  lest  we  become  involved  in 
some  terrible  inter-societary  struggle  and  find — 
like  Samson — when  we  arise  and  go  out  and 
shake  ourselves,  as  at  other  times  before,  that 
our  strength  has  gone  from  us  in  our  sleep. 


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